A histogram is an accurate representation of the distribution of numerical data. pandas.DataFrame.plot.hist¶ DataFrame.plot.hist (by = None, bins = 10, ** kwargs) [source] ¶ Draw one histogram of the DataFrameâs columns. Be careful when interpreting these, as all the axes are by default not shared, so both the Y and X axes are different, making it harder to compare offhand. You could use any base, like 2, or the natural logarithm value is given by the number e. Using different bases would narrow or widen the spacing of the plotted elements, making visibility easier. Default is None. Another way though is to use our original logged values, and change the format in the chart. Under Python you can easily create histograms in different ways. Like semilogx() or semilogy() functions and loglog() functions. For plotting histogram on a logarithmic scale, the bins are defined as ‘logbins.’ Also, we use non-equal bin sizes, such that they look equal on a log scale. The plot was of a histogram and the x-axis had a logarithmic scale. Although it is hard to tell in this plot, the data are actually a mixture of three different log-normal distributions. How To Set Log Scale. This takes up more room, so can pass in the figsize() parameter directly to expand the area of the plot. Histograms. Similarly, you can apply the same to change the x-axis to log scale by using pyplot.xscale(‘log’). With **subplot** you can arrange plots in a regular grid. Default (None) uses the standard line color sequence. At the very beginning of your project (and of your Jupyter Notebook), run these two lines: import numpy as np import pandas as pd. log - Whether the plot should be put on a logarithmic scale or not; This now results in: Since we've put the align to right, we can see that the bar is offset a bit, to the vertical right of the 2020 bin. A histogram is a chart that uses bars represent frequencies which helps visualize distributions of data. To normalize the areas for each subgroup, specifying the density option is one solution. Density plot on log-scale will reduce the long tail we see here. This is the modified version of the dataset that we used in the pandas histogram article â the heights and weights of our hypothetical gymâs members. (I think that is easier than building the legend yourself.). Currently hist2d calculates it's own axis limits, and any limits previously set are ignored. Note: To have the figure grid in logarithmic scale, just add the command plt.grid(True,which="both"). If you have only a handful of zeroes you may just want to do something like np.log([dat['x'].clip(1)) just to make a plot on the log scale, or some other negative value to make those zeroes stand out. 1. Matplotlib Log Scale Using Semilogx() or Semilogy() functions, Matplotlib Log Scale Using loglog() function, Scatter plot with Matplotlib log scale in Python, Matplotlib xticks() in Python With Examples, Python int to Binary | Integer to Binary Conversion, NumPy isclose Explained with examples in Python, Numpy Repeat Function Explained In-depth in Python, NumPy argpartition() | Explained with examples, NumPy Identity Matrix | NumPy identity() Explained in Python, How to Make Auto Clicker in Python | Auto Clicker Script, Apex Ways to Get Filename From Path in Python. The x-axis is log scaled, bypassing ‘log’ as an argument to the plt.xscale() function. Time Series plot is a line plot with date on y-axis. For a simple regression with regplot(), you can set the scale with the help of the Axes object. 2. by object, optional. Hello programmers, in today’s article, we will learn about the Matplotlib Logscale in Python. Using Log Scale with Matplotlib Histograms; Customizing Matplotlib Histogram Appearance; Creating Histograms with Pandas; Conclusion; What is a Histogram? Great! The base of the logarithm for the X-axis and Y-axis is set by basex and basey parameters. (Although note if you are working with low count data that can have zeroes, a square root transformation may make more sense. But I often want the labels to show the original values, not the logged ones. You could use any base, like 2, or the natural logarithm value is given by the number e. Using different bases would narrow or widen the spacing of the plotted elements, making visibility easier. Let us load the packages needed to make line plots using Pandas. Using the sashelp.cars data set, the first case on the right shows a histogram of the original data in linear space, on a LOG x axis. And donât forget to add the: %matplotlib â¦ We can change to log-scale on x-axis by setting logx=True as argument inside plot.density() function. column: string or sequence. So another option is to do a small multiple plot, by specifying a by option within the hist function (instead of groupby). During the data exploratory exercise in your machine learning or data science project, it is always useful to understand data with the help of visualizations. You can modify the scale of your axes to better show trends. The plt.scatter() function is then called, which returns the scatter plot on a logarithmic scale. This is a linear, logarithmic graph. I also show setting the pandas options to a print format with no decimals. Set a log scale on the data axis (or axes, with bivariate data) with the given base (default 10), and evaluate the KDE in log space. While the semilogy() function creates a plot with log scaling along Y-axis. When you do it this way, you want to specify your own bins for the histogram. hist â Output histogram, which is a dense or sparse dims-dimensional array. So I have a vector of integers, quotes , which I wish to see whether it observes a power law distribution by plotting the frequency of data points and making both the x and y axes logarithmic. While the plt.semilogy() function changes the y-axis to base 2 log scale. It may not be obvious, but using pandas convenience plotting functions is very similar to just calling things like ax.plot or plt.scatter etc. 2. The Python histogram log argument value accepts a boolean value, and its default is False. Matplotlib log scale is a scale having powers of 10. In this tutorial, we've gone over several ways to plot a histogram plot using Matplotlib and Python. Default is False. Plotting a Logarithmic Y-Axis from a Pandas Histogram Note to self: How to plot a histogram from Pandas that has a logarithmic y-axis. If False, suppress the legend for semantic variables. Links Site; pyplot: Matplotlib doc: Matplotlib how to show logarithmically spaced grid lines at all ticks on a log-log plot? Je développe le présent site avec le framework python Django. Also plotting at a higher alpha level lets you see the overlaps a bit more clearly. (I use spyder more frequently than notebooks, so it often cuts off the output.) A better way to make the density plot is to change the scale of the data to log-scale. Histogram with Logarithmic Scale and custom breaks (7 answers) Closed 7 years ago . If you omit the formatter option, you can see the returned values are 10^2, 10^3 etc. Using layout parameter you can define the number of rows and columns. The margins of the plot are huge. The taller the bar, the more data falls into â¦ Customizing Histogram in Pandas Now the histogram above is much better with easily readable labels. If log is True and x is a 1D array, empty bins will be filtered out and only the non-empty (n, bins, patches) will be returned. Then I create some fake log-normal data and three groups of unequal size. The defaults are no doubt ugly, but here are some pointers to simple changes to formatting to make them more presentation ready. Fill in your details below or click an icon to log in: You are commenting using your WordPress.com account. import matplotlib.pyplot as plt import numpy as np matplotlib.pyplot.hist the histogram axis will be set to a log scale. import pandas as pd import numpy as np from vega_datasets import data import matplotlib.pyplot as plt 3142 def set_yscale (self, value, ** kwargs): 3143 """ 3144 Call signature:: 3145 3146 set_yscale(value) 3147 3148 Set the scaling of the y-axis: %(scale)s 3149 3150 ACCEPTS: [%(scale)s] 3151 3152 Different kwargs are accepted, depending on the scale: 3153 %(scale_docs)s 3154 """ 3155 # If the scale is being set to log, clip nonposy to prevent headaches 3156 # around zero 3157 if value. If True, the histogram axis will be set to a log scale. Histograms,Demonstrates how to plot histograms with matplotlib. Sometimes, we may want to display our histogram in log-scale, Let us see how can make our x-axis as log-scale. Use the right-hand menu to navigate.) log_scale bool or number, or pair of bools or numbers. It is one of the most popular and widely used Python data visualization libraries, and it is compatible with other Python Data Science Libraries like numpy, sklearn, pandas, PyTorch, etc. And base 2 log scaling along the y-axis. Apart from this, there is one more argument called cumulative, which helps display the cumulative histogram. Letâs start by downloading Pandas, Pyplot from matplotlib and Seaborn to [â¦] ( Log Out / This function calls matplotlib.pyplot.hist(), on each series in the DataFrame, resulting in one histogram per column. Color spec or sequence of color specs, one per dataset. The process of plot logarithmic axes is similar to regular plotting, except for one line of code specifying the type of axes as ‘log.’ In the above example, we first set up the subplot required plot the graph. In the above example, basex = 10 and basey = 2 is passed as arguments to the plt.loglog() function which returns the base 10 log scaling x-axis. One way to compare the distributions of different groups are by using groupby before the histogram call. We will then plot the powers of 10 against their exponents. color: color or array_like of colors or None, optional. palette string, list, dict, or matplotlib.colors.Colormap So here is an example of adding in an X label and title. Now onto histograms. By using the "bottom" argument, you can make sure the bars actually show up. â¦ We also cited examples of using Matplotlib logscale to plot to scatter plots and histograms. (This article is part of our Data Visualization Guide. Change ), You are commenting using your Twitter account. stackoverflow: Add a comment * Please log-in to post a comment. The pandas object holding the data. ( Log Out / Python Histogram - 14 examples found. Change ), You are commenting using your Facebook account. So typically when I see this I do a log transform. This function groups the values of all given Series in the DataFrame into bins and draws all bins in one matplotlib.axes.Axes. Output:eval(ez_write_tag([[320,100],'pythonpool_com-large-leaderboard-2','ezslot_8',121,'0','0'])); In the above example, the Histogram plot is once made on a normal scale. Change ). So you can assign the plot to an axes object, and then do subsequent manipulations. Matplotlib log scale is a scale having powers of 10. Log and natural logarithmic value of a column in pandas python is carried out using log2 (), log10 () and log ()function of numpy. Here I also show how you can use StrMethodFormatter to return a money value. Ordinarily a "bottom" of 0 will result in no bars. In the above example, the axes are the first log scaled, bypassing ‘log’ as a parameter to the ser_xscale() and set_yscale() functions. So far, I have plotted the logged values. So if you are following along your plots may look slightly different than mine. Introduction. The logarithmic scale is useful for plotting data that includes very small numbers and very large numbers because the scale plots the data so you can see all the numbers easily, without the small numbers squeezed too closely. Here are some notes (for myself!) Although histograms are considered to be some of the â¦ The Y axis is not really meaningful here, but this sometimes is useful for other chart stats as well. We can use the Matlplotlib log scale for plotting axes, histograms, 3D plots, etc. Using the schema browser within the editor, make sure your data source is set to the Mode Public Warehouse data source and run the following query to wrangle your data:Once the SQL query has completed running, rename your SQL query to Sessions so that you can easiâ¦ np.random.seed(0) mu = 170 #mean sigma = 6 #stddev sample = 100 height = np.random.normal(mu, sigma, sample) weight = (height-100) * np.random.uniform(0.75, 1.25, 100) This is a random generator, by the way, that generates 100 height â¦ Histograms are excellent for visualizing the distributions of a single variable and are indispensable for an initial research analysis with fewer variables. It is an estimate of the probability distribution of a continuous variable and was first introduced by Karl Pearson. And note I change my default plot style as well. Unfortunately I keep getting an error when I specify legend=True within the hist() function, and specifying plt.legend after the call just results in an empty legend. If passed, will be used to limit data to a subset of columns. column str or sequence. Plotly Fips ... Plotly Fips ; The log scale draws out the area where the smaller numbers occur. about how to format histograms in python using pandas and matplotlib. matplotlib Cumulative Histogram. Matplotlib is the standard data visualization library of Python for Data Science. Refer to this article in case of any queries regarding the use of Matplotlib Logscale.eval(ez_write_tag([[300,250],'pythonpool_com-leader-1','ezslot_1',122,'0','0']));eval(ez_write_tag([[300,250],'pythonpool_com-leader-1','ezslot_2',122,'0','1'])); However, if you have any doubts or questions, do let me know in the comment section below. In this article, we will explore the following pandas visualization functions â bar plot, histogram, box plot, scatter plot, and pie chart. Step 1: convert the column of a dataframe to float # 1.convert the column value of the dataframe as floats float_array = df['Score'].values.astype(float) Step 2: create a min max processing object.Pass the float column to the min_max_scaler() which scales the dataframe by processing it as shown below The panda defaults are no doubt good for EDA, but need some TLC to make more presentation ready. References. https://andrewpwheeler.com/2020/08/11/histogram-notes-in-python-with-pandas-and-matplotlib/. Let’s take a look at different examples and implementations of the log scale. However, if the plt.scatter() method is used before log scaling the axes, the scatter plot appears normal. If you set this True, then the Matplotlib histogram axis will be set on a log scale. We have seen different functions to implement log scaling to axes. And also plotted on Matplotlib log scale. ), Much better! Rendering the histogram with a logarithmic color scale is accomplished by passing a colors.LogNorm instance to the norm keyword argument. Histogram of the linear values, displayed on a log x axis. 2.1 Stacked Histograms. A histogram is an accurate representation of the distribution of numerical data. One is to plot the original values, but then use a log scale axis. If passed, will be used to limit data to a subset of columns. Pandasâ plotting capabilities are great for quick exploratory data visualisation. One of the advantages of using the built-in pandas histogram function is that you donât have to import any other libraries than the usual: numpy and pandas. Well that is not helpful! Also rotate the labels so they do not collide. We can use the Matlplotlib log scale for plotting axes, histograms, 3D plots, etc. Pandas has many convenience functions for plotting, and I typically do my histograms by simply upping the default number of bins. We can also implement log scaling along both X and Y axes by using the loglog() function. In this article, we have discussed various ways of changing into a logarithmic scale using the Matplotlib logscale in Python. When normed is True, then the returned histogram is the sample density, defined such that the sum over bins of the product bin_value * bin_area is 1. First, here are the libraries I am going to be using. Python Plot a Histogram Using Python Matplotlib Library. Here we can do that using FuncFormatter. legend bool. Daidalos. #Can add in all the usual goodies ax = dat ['log_vals'].hist (bins=100, alpha=0.8) plt.title ('Histogram on Log Scale') ax.set_xlabel ('Logged Values') Although it is hard to tell in this plot, the data are actually a mixture of three different log-normal distributions. Advanced Criminology (Undergrad) Crim 3302, Communities and Crime (Undergrad) Crim 4323, Crim 7301 – UT Dallas – Seminar in Criminology Research and Analysis, GIS in Criminology/Criminal Justice (Graduate), Crime Analysis (Special Topics) – Undergrad, An example of soft constraints in linear programming, Using Steiner trees to select a subgraph of interest, Notes on making scatterplots in matplotlib and seaborn | Andrew Wheeler, Checking a Poisson distribution fit: An example with officer involved shooting deaths WaPo data (R functions), The WDD test with different pre/post time periods, New book: Micro geographic analysis of Chicago homicides, 1965-2017, Testing the equality of two regression coefficients, Using Python to grab Google Street View imagery. Here we are plotting the histograms for each of the column in dataframe for the first 10 rows(df[:10]). But you see here two problems, since the groups are not near the same size, some are shrunk in the plot. Letâs see how to Get the natural logarithmic value of column in pandas (natural log â loge ()) Get the logarithmic value of the column in pandas with base 2 â log2 () Here we see examples of making a histogram with Pandace and Seaborn. Make a histogram of the DataFrameâs. For this example, youâll be using the sessions dataset available in Modeâs Public Data Warehouse. Likewise, power-law normalization (similar in effect to gamma correction) can be accomplished with colors.PowerNorm. We can use matplotlibâs plt object and specify the the scale of â¦ Without the logarithmic scale, the data plotted would show a curve with an exponential rise. If log is True and x is a 1D array, empty bins will be filtered out and only the non-empty On the slate is to do some other helpers for scatterplots and boxplots. When displayed on a log axis, the bins are drawn with varying pixel width. Besides log base 10, folks should often give log base 2 or log base 5 a shot for your data. Python Pandas library offers basic support for various types of visualizations. Change ), You are commenting using your Google account. ( Log Out / In the above example, the plt.semilogx() function with default base 10 is used to change the x-axis to a logarithmic scale. Thus to obtain the y-axis in log scale, we will have to pass ‘log’ as an argument to the pyplot.yscale(). Conclusion. Parameters: data: DataFrame. There are two different ways to deal with that. This histogram has equal width bins in linear data space. 2.1 Stacked Histograms. The second is I don’t know which group is which. We can, however, set the base with basex and basey parameters for the function semilogx() and semilogy(), respectively. Histograms. Parameters data DataFrame. It is an estimate of the probability distribution of a continuous variable and was first introduced by Karl Pearson. You need to specify the number of rows and columns and the number of the plot. Besides the density=True to get the areas to be the same size, another trick that can sometimes be helpful is to weight the statistics by the inverse of the group size. Make a histogram of the DataFrameâs. Going back to the superimposed histograms, to get the legend to work correctly this is the best solution I have come up with, just simply creating different charts in a loop based on the subset of data. The default base of the logarithm is 10. A histogram is a representation of the distribution of data. A histogram is a representation of the distribution of data. Enter your email address to follow this blog and receive notifications of new posts by email. Set a log scale on the data axis (or axes, with bivariate data) with the given base (default 10), and evaluate the KDE in log space. The pandas object holding the data. Thatâs why it might be useful in some cases to use the logarithmic scale on one or both axes. The semilogx() function is another method of creating a plot with log scaling along the X-axis. A histogram is a representation of the distribution of data. Bars can represent unique values or groups of numbers that fall into ranges. numpy and pandas are imported and ready to use. But I also like transposing that summary to make it a bit nicer to print out in long format. Happy Pythoning!eval(ez_write_tag([[320,50],'pythonpool_com-large-mobile-banner-1','ezslot_0',123,'0','0'])); Python Pool is a platform where you can learn and become an expert in every aspect of Python programming language as well as in AI, ML and Data Science. ( Log Out / One trick I like is using groupby and describe to do a simple textual summary of groups. (Don’t ask me when you should be putzing with axes objects vs plt objects, I’m just muddling my way through.). This function calls matplotlib.pyplot.hist(), on each series in the DataFrame, resulting in one histogram per column. Pandas Subplots. I will try to help you as soon as possible. Youâll use SQL to wrangle the data youâll need for our analysis. Density Plot on log-scale with Pandas . Of a continuous variable and are indispensable for an initial research analysis with fewer variables convenience plotting functions is similar! Notifications of new posts by email simple regression with regplot ( ) function changes y-axis. I see this I do a log X axis variable and was first introduced by Karl.... Your data histogram note to self: how to format histograms in Python areas each. Base 10, folks should often give log base 5 a shot for your data can represent unique values groups... 'Ve gone over several ways to deal with that histograms by simply upping the default number of and. Chart stats as well ’ s take a look at different examples and implementations of distribution. Limits, and change the scale of the column in DataFrame for the x-axis y-axis! Using Pandas introduced by Karl Pearson the Matlplotlib log scale while the plt.semilogy ( ) parameter to... Transposing that summary to make them more presentation ready into bins and draws all bins in linear data space x-axis... Have plotted the logged ones pyplot: Matplotlib doc: Matplotlib how to show original. Histograms are considered to be using of groups fake log-normal data and three groups of numbers fall! Have the figure grid in logarithmic scale using the `` bottom '' of will! This takes up pandas histogram log scale room, so it often cuts off the Output. ) new posts email. Y-Axis to base 2 or log base 5 a shot for your data ( None uses... Support for various types of visualizations have plotted the logged values, not the logged values, I. A regular grid it 's own axis limits, and any limits previously set are ignored here problems... To compare the distributions of data better way to compare the distributions of a continuous and! Histogram Appearance ; Creating histograms with Matplotlib histograms ; Customizing Matplotlib histogram Appearance ; Creating with! Or log base 2 log scale is a scale having powers of 10 against their exponents are commenting using WordPress.com. The Matplotlib histogram Appearance ; Creating histograms with Pandas ; Conclusion ; is. Change to log-scale slate is to do some other helpers for scatterplots and boxplots Creating a with... Has a logarithmic scale regplot ( ) function changes the y-axis to base 2 log. Offers basic support for various types of visualizations X and Y axes by using pyplot.xscale ( log..., let us see how can make sure the bars actually show up without the logarithmic scale, plt.semilogx... This I do a simple textual summary of groups plt.semilogy ( ) functions and loglog ( function! Libraries I am going to be some of the column in DataFrame for the to... Have zeroes, a square root transformation may make more presentation ready of numerical data: to the... Notifications of new posts by email subsequent manipulations can be accomplished with colors.PowerNorm None, optional but then a! Do a simple textual summary of groups specs, one per dataset so it often cuts off the Output )... Public data Warehouse ( 7 answers ) Closed 7 years ago / change ), on each in. There is one more argument called cumulative, which returns the scatter plot on log-scale will reduce the tail... Some TLC to make line plots using Pandas 10 rows ( df:10! Represent unique values or groups of numbers that fall into ranges labels to show logarithmically spaced lines. Colors or None, optional to use semilogy ( ) function creates a plot with date on y-axis and. Load the packages needed to make the density option is one more argument called cumulative which. '' of 0 will result in no bars so you can set the scale the.: % Matplotlib â¦ if True, which= '' both '' ) take a at., since the groups are not near the same size, some are shrunk in the DataFrame, resulting one. The help of the column in DataFrame for the x-axis to a subset of columns but this sometimes is for. Show the original values, displayed on a logarithmic color scale is a representation of distribution... Here is an estimate of the data plotted would show a curve with an exponential rise create histograms different! S article, we have seen different functions to implement log scaling axes. Présent Site avec le framework Python Django and three groups of numbers that fall into ranges to norm. Then use a log scale for plotting axes, the scatter plot on a log X axis Pandas. You can apply the same size, some are shrunk in the DataFrame into bins and all... Histograms ; Customizing Matplotlib histogram axis will be set pandas histogram log scale a logarithmic,. Histogram axis will be set on a log axis, the scatter plot on log-scale with Pandas Conclusion... Plt.Grid ( True, the histogram function is another method of Creating a with... Scale of the axes, histograms, 3D plots, etc x-axis y-axis! Calls matplotlib.pyplot.hist ( ), you are commenting using your WordPress.com account other... Different log-normal distributions, so it often cuts off the Output. ) accepts. You see here two problems, since the groups pandas histogram log scale not near the same size, some are shrunk the... The above example, youâll be using log scaled, bypassing ‘ ’. Show how you can define the number of rows and columns and number... Logarithmically spaced grid lines at all ticks on a log-log plot Pandas has convenience. Am going to be some of the distribution of data chart that uses bars represent which... With an exponential rise ) or semilogy ( ) function with default base is! Time series plot is to change the scale of your axes to better show.. ), you are working with low count data that can have zeroes, a square root may... Do it this way, you are commenting using your Twitter account scaling to axes along y-axis plot as. Dense or sparse dims-dimensional array with Pandace and Seaborn to [ â¦ ] 2 change ), can... Into a logarithmic scale and custom breaks ( 7 answers ) Closed years! More frequently than notebooks, so can pass in the plot here are the libraries I am going to using... A higher alpha level lets you see here two problems, since the groups are not near same! Color scale is a representation of the log scale we see here two problems, since the are! You can easily create histograms in different ways to deal with that,! Histograms are considered to be some of the distribution of data by setting logx=True as argument plot.density. Great for quick exploratory data visualisation ready to use our original logged values, the! Histograms for each subgroup, specifying the density plot is a representation of the of... Plot on log-scale will reduce the long tail we see examples of making a is. With Matplotlib three different log-normal distributions summary to make line plots using Pandas than notebooks, so can pass the! Useful in some cases to use the default number of rows and columns and number... Transposing that summary to make the density plot on a log scale is a plot..., let us load the packages needed to make the density option is one solution is by. Called cumulative, which helps display the cumulative histogram the column in DataFrame for the and. To expand the area of the data are actually a mixture of three different log-normal distributions see examples making... To be some of the logarithm for the histogram with logarithmic scale on one or both.... Output histogram, which is a representation of the distribution of a continuous variable and was first introduced Karl! Draws all bins in linear data space a log-log plot offers basic support for various types of visualizations look different. The logged ones ordinarily a `` bottom '' argument, you can plots... Histogram log argument value accepts a boolean value, and then do subsequent manipulations have zeroes a! Of the data plotted would show a curve with an exponential rise ) uses the standard data Visualization.. Email address to follow this blog and receive notifications of new posts by email directly to expand the area the. Pandas ; Conclusion ; What is a dense or sparse dims-dimensional array log... For each subgroup, specifying the density plot on a log scale in linear data space so! Used before log scaling along the x-axis and y-axis is set by basex basey.: Matplotlib doc: Matplotlib how to format histograms in different ways on the slate is to our. LetâS start by downloading Pandas, pyplot from Matplotlib and Python are using! 0 will result in no bars can modify the scale with the help of the for... Email address to follow this blog and receive notifications of new posts by email think that is easier building... ] 2 color: color or array_like of colors or None,.! With no decimals groups the values of all given series in the DataFrame into bins and all... Each of the â¦ Pandasâ plotting capabilities are great for quick exploratory data visualisation they... I think that is easier than building the legend yourself. ) a log scale can apply the same change! Want the labels to show logarithmically spaced grid lines at all ticks on a log,... In today ’ s article, we have seen different functions to implement log along. This example, the histogram with logarithmic scale using the sessions dataset available in Public... But then use a log scale is accomplished by passing a colors.LogNorm instance the... Setting logx=True as argument inside plot.density ( ) or semilogy ( ) function there.