[Matplotlib-users] A request for a Matplotlib extension to hist
I have some Python (2.7.9) code that processes some rather large data sets to determine the curvatures along 2D curves. One feature of these data that I like to look at is the distribution of the curvatures. I use NumPy to to determine histograms for each set, and save the histogram parameters returned from numpy.histogram in a file. I would like to use Matplotlib to plot histograms *from the parameters returned in NumPy* and stored in a file --- why? Because the size of my data sets does not allow for the use of the histogram plot function in Matplotlib (1.4.3); i.e., it needs the data sets to calculate the histogram, before doing the plot. I would like to have a histogram plot function in Matplotlib that could bypass the actual calculation of the bin counts and edges from the data, and use values of these found /a priori/. Of course, an obvious question is -- Why not write code to plot the rectangles yourself? Yes, I could do this; but, why not extend the Matplotlib histogram class to allow for this option? If I better understood Matplotlib, I would try this myself. Maybe it is possible to get this into the next planned release (1.5).:-) If this request is inappropriate for this list, then please accept my apology and direct me to where I should send this request. Best regards. -- One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] A request for a Matplotlib extension to hist
On 24-Apr-2015 12:58, Christian Alis wrote: I had the same problem some time ago and what I did is to use bar() to plot the histogram, which can be done in one line: hist, bin_edges = np.histogram(data) plt.bar(bin_edges[:-1], hist) Very elegant Christian :-) Perhaps this trick can be added in the documentation? Well, I vote to add it. However, I did find the following nice example (after reading your email) that shows how the bar function might be used (http://matplotlib.org/examples/api/barchart_demo.html) for my problem. Had I seen this before, I probably would not have posted this request.:-[ I am willing to code Virgil's request if many will find this useful. On Fri, Apr 24, 2015 at 11:33 AM, Virgil Stokes v...@it.uu.se wrote: I have some Python (2.7.9) code that processes some rather large data sets to determine the curvatures along 2D curves. One feature of these data that I like to look at is the distribution of the curvatures. I use NumPy to to determine histograms for each set, and save the histogram parameters returned from numpy.histogram in a file. I would like to use Matplotlib to plot histograms from the parameters returned in NumPy and stored in a file --- why? Because the size of my data sets does not allow for the use of the histogram plot function in Matplotlib (1.4.3); i.e., it needs the data sets to calculate the histogram, before doing the plot. I would like to have a histogram plot function in Matplotlib that could bypass the actual calculation of the bin counts and edges from the data, and use values of these found a priori. Of course, an obvious question is -- Why not write code to plot the rectangles yourself? Yes, I could do this; but, why not extend the Matplotlib histogram class to allow for this option? If I better understood Matplotlib, I would try this myself. Maybe it is possible to get this into the next planned release (1.5). :-) If this request is inappropriate for this list, then please accept my apology and direct me to where I should send this request. Best regards. -- One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users Keep up the good work on Matplotlib and I look forward to vers. 1.5 :-) -- One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] A request for a Matplotlib extension to hist
I had the same problem some time ago and what I did is to use bar() to plot the histogram, which can be done in one line: hist, bin_edges = np.histogram(data) plt.bar(bin_edges[:-1], hist) Perhaps this trick can be added in the documentation? I am willing to code Virgil's request if many will find this useful. On Fri, Apr 24, 2015 at 11:33 AM, Virgil Stokes v...@it.uu.se wrote: I have some Python (2.7.9) code that processes some rather large data sets to determine the curvatures along 2D curves. One feature of these data that I like to look at is the distribution of the curvatures. I use NumPy to to determine histograms for each set, and save the histogram parameters returned from numpy.histogram in a file. I would like to use Matplotlib to plot histograms from the parameters returned in NumPy and stored in a file --- why? Because the size of my data sets does not allow for the use of the histogram plot function in Matplotlib (1.4.3); i.e., it needs the data sets to calculate the histogram, before doing the plot. I would like to have a histogram plot function in Matplotlib that could bypass the actual calculation of the bin counts and edges from the data, and use values of these found a priori. Of course, an obvious question is -- Why not write code to plot the rectangles yourself? Yes, I could do this; but, why not extend the Matplotlib histogram class to allow for this option? If I better understood Matplotlib, I would try this myself. Maybe it is possible to get this into the next planned release (1.5). :-) If this request is inappropriate for this list, then please accept my apology and direct me to where I should send this request. Best regards. -- One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users -- One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] A request for a Matplotlib extension to hist
Le 24/04/2015 12:58, Christian Alis responds to the problem posed by Virgil Stokes I had the same problem some time ago and what I did is to use bar() to plot the histogram, which can be done in one line: hst, bin_edges = np.histogram(data) plt.bar(bin_edges[:-1], hst) Perhaps this trick can be added in the documentation? I am willing to code Virgil's request if many will find this useful. Separating the computation of the histogram, and plotting it is obviously useful. (I needed this in a linguistical simulation context, where plotting had no sense). Actually hist is more or less this, see _axes.py, line 5678, the Axes method hist just calls numpy.histogram. And then plots bars (or uses some other style). So, although completing the documentation might be of general interest, I would NOT recommend adding some new version of hist. This would be misleading. Hist is hist is hist(ogram). It computes the histogram (and eventually plots it). If it is already computed elsewhere, naming the procedure which JUST plots some bars a histogram is methodologically very dubious. Jerzy Karczmarczuk -- One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
Re: [Matplotlib-users] A request for a Matplotlib extension to hist
Hi, I think there is a good reason to add the functionality to plot pre-computed histograms to hist() or to a new function with similar API. Sometimes histograms are heavy or we don't want to recompute them to perform a series of plots. In this case, I miss the ability to easily set the plot style. hist() allows to chose between bar, step and stepfilled. To change the style with pre-computed histograms, I need to write 3 different plots using bar(), plot() and fill_between() respectively. This is quite inconvenient and error prone, considering that these function have different API for the input data. Maybe the plotting part of hist() should be splitted in a standalone function (plotbins() ?) In this way, hist() can call this function to generate the plot, but also the user can call it when the histogram is pre-computed. The bonus is that we retain the same API for plot style. My 2cents, Antonio On Fri, Apr 24, 2015 at 4:31 AM, Jerzy Karczmarczuk jerzy.karczmarc...@unicaen.fr wrote: Le 24/04/2015 12:58, Christian Alis responds to the problem posed by Virgil Stokes I had the same problem some time ago and what I did is to use bar() to plot the histogram, which can be done in one line: hst, bin_edges = np.histogram(data) plt.bar(bin_edges[:-1], hst) Perhaps this trick can be added in the documentation? I am willing to code Virgil's request if many will find this useful. Separating the computation of the histogram, and plotting it is obviously useful. (I needed this in a linguistical simulation context, where plotting had no sense). Actually hist is more or less this, see _axes.py, line 5678, the Axes method hist just calls numpy.histogram. And then plots bars (or uses some other style). So, although completing the documentation might be of general interest, I would NOT recommend adding some new version of hist. This would be misleading. Hist is hist is hist(ogram). It computes the histogram (and eventually plots it). If it is already computed elsewhere, naming the procedure which JUST plots some bars a histogram is methodologically very dubious. Jerzy Karczmarczuk -- One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y ___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users -- One dashboard for servers and applications across Physical-Virtual-Cloud Widest out-of-the-box monitoring support with 50+ applications Performance metrics, stats and reports that give you Actionable Insights Deep dive visibility with transaction tracing using APM Insight. http://ad.doubleclick.net/ddm/clk/290420510;117567292;y___ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
