matplotlib-users Mailing List for matplotlib

>>>>> "Engelsma," == Engelsma, Dave <D.E...@La...> writes:

    Engelsma,> Any ideas?

The following script, all negative data, works fine for me:

    from matplotlib.matlab import *

    x = randn(1000)-10
    hist(x, 10)
    show()

Make sure this example works for you (if not upgrade matplotlib), and
then go back to your example.  Take out all the customization stuff
after the call to

	n, bins, patches = matplotlib.matlab.hist(histogram_data, 10,
normed=0)

and see if that works.  If so, slowly add things back until you find
out what is wrong.  If it's a matplotlib error rather than an error on
your side, let me know.

JDH

Hello -

I'm creating a histogram with a negative data values (30 values between -1.5
and -0.5). The histogram is created, however the data is plotted as if the
values were forced positive (i.e. forced to absolute values).

I've checked exactly what data is being passed to the hist function and the
data goes in as a series of negative values.

The Python code:

	# Generate chart using matplotlib library
	histogram_data = array.array('f')
	histogram_data.fromlist(DimensionData)
	overall_range = max(DimensionData) - min(DimensionData)
	x_lowest = min(DimensionData) - (2*overall_range)
	x_highest = max(DimensionData) + (2*overall_range)

	# the histogram of the data
	n, bins, patches = matplotlib.matlab.hist(histogram_data, 10,
normed=0)
	histogram = matplotlib.matlab.subplot(111)

	# add a 'best fit' line
	y = matplotlib.mlab.normpdf(bins, SC.meanVal, SC.stdDev)
	lines = histogram.plot(bins, y, 'r-')
	for line in lines:
		line.set_linewidth(1)

	# plot lines on histogram indicating upper & lower control limits
along with 
	#   nominal dimension.
	histogram.set_xlim([x_lowest, x_highest])
	histogram.plot([SC.LCL,SC.LCL],[0,max(n)],'b--')
	histogram.plot([SC.Nom,SC.Nom],[0,max(n)],'g--')
	histogram.plot([SC.UCL,SC.UCL],[0,max(n)],'r--')

	# Set axis labels
	histogram.set_xlabel(DataDesc)
	histogram.set_ylabel('Number of Parts')

	# Setup strings for chart legend
	LegUCL = "UCL: " + str(SC.UCL)
	LegNom = "Nominal: " + str(SC.Nom)
	LegLCL = "LCL: " + str(SC.LCL)

	histogram.legend(["Curve", LegLCL, LegNom, LegUCL],fontsize = 10)
	histogram.set_xlim([x_lowest, x_highest])
	
	#matplotlib.matlab.savefig(filePath)
	matplotlib.matlab.show()
	matplotlib.matlab.close()

Any ideas?

Thanks in advance,

Dave Engelsma
Lacks Wheel Trim Systems

Hey.  We are using Matplotlib with Python and C to create run time
graphs.  However, we are having trouble figuring out how to get the axes
to show up in scientific notation.  If anyone have some info it would be
very much appreciated.  Thanks
 

Hi,
I am simulating the movement of some particles that carry some
concentration of different species. Those concentrations change in time
and space and I would like to be able to see their distribution in
space. 

I am using the scatter plot of Matplotlib to plot the position of each
particle. That works great, but when I try to assign different colors to
each dot according to their concentration I find some problems. Although
there is a big range of concentrations (colors) I can only see two in
the plot. Is it possible to define more intervals to assign the colors?
I think I did not understand the right way to define the c array
intensities when I use the command:  
scatter(self, x, y, s=None, c)
How should I generate that array? I looked at the example but I couldn't
figure it out.

Thanks for your help,
I look forward to see the future versions of Matplotlib. So far, it
looks very good.
Paulo.