Matplotlib: Horizontal Linelength in Legend - matplotlib

Lets say i'm plotting a line with matplotlib and add a legend.
Within the legend it says ------ Label. I find the default horizontal length of this line a bit too long when plotting small figure sizes for print.
Is there a property to set ------ Label to --- Label?

When you create your legend add the handlelength keyword (doc) which sets the length of the '---' (which is called the handle).

Related

TramineR legend position and axis

I'm working with TraMineR and I don't know how to arrange my plot. So basically what i would like to have the legend under the plot and to remove the space between the x and y axis. Any help is welcomed.
The plot:
Sample code:
seqdplot(Activities.seq, with.legend=FALSE)
legend("bottom", legend=attr(Activities.seq, "labels"),
fill=attr(Activities.seq, "cpal"),
inset=-.1, bty="o", xpd=NA, cex=.75,ncol=3)
The family of seqplot functions offers a series of arguments to control the legend as well as the axes. Look at the help page of seqplot (and of plot.stslist.statd for specific seqdplot parameters).
For instance, you can suppress the x-axis with axes=FALSE, and the y-axis with yaxis=FALSE.
To print the legend you can let seqdplot display it automatically using the default with.legend=TRUE option and control it with for examples cex.legend for the font size, ltext for the text. You can also use the ncol argument to set the number of columns in the legend.
The seqplot functions use by default layout to organize the graphic area between the plots and the legend. If you need more fine tuning (e.g. to change the default par(mar=c(5.1,4.1,4.1,2.1)) margins around the plot and the legend), you should create separately the plot(s) and the legend and then organize them yourself using e.g. layout or par(mfrow=...). In that case, the separate graphics should be created by setting with.legend=FALSE, which prevents the display of the legend and disables the automatic use of layout.
The color legend is easiest obtained with seqlegend.
I illustrate with the mvad data that ships with TraMineR. First the default plot with the legend. Note the use of border=NA to suppress the too many vertical black lines.
library(TraMineR)
data(mvad)
mvad.scode <- c("EM", "FE", "HE", "JL", "SC", "TR")
mvad.seq <- seqdef(mvad, 17:86,
states = mvad.scode,
xtstep = 6)
# Default plot with the legend,
seqdplot(mvad.seq, border=NA)
Now, we suppress the x and y axes and modify the display of the legend
seqdplot(mvad.seq, border=NA,
axes=FALSE, yaxis=FALSE, ylab="",
cex.legend=1.3, ncol=6, legend.prop=.11)
Here is how you can control the space between the plot and the x and y axes
seqdplot(mvad.seq, border=NA, yaxis=FALSE, xaxis=FALSE, with.legend=FALSE)
axis(2, line=-1)
axis(1, line=0)
Creating the legend separately and reducing the left, top, and right margins around the legend
op <- par(mar=c(5.1,0.1,0.1,0.1))
seqlegend(mvad.seq, ncol=2, cex=2)
par(op)

matplotlib: plot or scatter without line through marker

is there a simple way to have scatter() plots (or just plots) with data points shown by some marker and connected by lines, but, when markerfacecolor='none' (or facecolor=none) have the line not shown within the area of the marker.
E.g.:
xx = arange(0.0,10.0,0.5)
yy = sin(xx)
plt.plot(xx,yy,'k-',marker='o',markerfacecolor='none')
results in the following figure.
But I would like the lines connecting data points to start not from the center of each marker but from its borders.

matplotlib tick labels position relative to axes

I set matplotlib to put ticks outside the plot area but now they overlap on the corresponding labels. the tick_params method does not provide any option to set the corresponding labels position.
So I guess I will have to write my own function using text() method. In the meanwhile does any one has a better suggestion?
To shift the tick labels relative to the ticks use pad. Compare
ax.tick_params(direction='out', pad=5)
plt.draw()
with
ax.tick_params(direction='out', pad=15)
plt.draw()

How to create a scatter plot legend with only one symbol for each label?

How can I create a scatter plot legend without two symbols showing up each time? I can understand why you'd want this when you're joining symbols by lines, but for a pure scatter plot, all I want in the legend is one example of the symbol. This plot from a previous stackoverflow post shows the kind of thing I mean:
In the legend command you can use the scatterpoints option:
ax.legend(loc=0, scatterpoints = 1)
For a normal plot, it is the option numpoints.
Here you can find more information about the keyword arguments for the legend: http://matplotlib.sourceforge.net/api/pyplot_api.html#matplotlib.pyplot.legend

matplotlib numbers in legend

I have a couple of lines and I want to show a legend. The problem is, I can't use different styles (--, :, -.) because there are too few of them, and I can't use markers (+, *, etc.) because I need them to show some points on the lines.
So the best idea I've come up with is to use numbers. But I can't figure how I can create legends with numbers. I can even draw numbers near lines myself (to place them in the best position), but how can I then draw a legend with the numbers?
I.e. instead of:
-- H
-.- Li
I'd like something like:
1 H
2 Li
Perhaps a little Latex thrown into the mix?
#In which we make a legend; not with lines, but numbers!
import pylab as pl
pl.rc('text', usetex=True)
pl.figure(1)
pl.clf()
ax = pl.subplot(111)
pl.plot(range(0,10), 'k', label = r'\makebox[25]{1\hfill}Bla')
pl.plot(range(1,11), 'k', label = r'\makebox[25]{12\hfill}Bla12')
lgd = pl.legend(handlelength = -0.4)
for k in lgd.get_lines():
k.set_linewidth(0)
pl.draw()
pl.show()
The numbers/labels are aligned by using \makebox with specific width and \hfill to take up the space not used by your labels. Numbers are not automatic, but if you use a loop to draw your lines then you could add a counter to keep track of the numbers.
Don't know if this is part of your requirement, but the lines are removed by setting their linewidth to 0 and making the space reserved in the legend negative. Couldn't find a neater way of doing this as I believe a legend is always meant to show a line (e.g. you can't set numpoints to 0).
You could of course also just add some text in the right spot in your plot and not use a legend at all.