As seen, the default colour in map-view in Gnuplot for zero value is black. I want to make it white and display other colours for other data. May you tell me how to customise the colours please? Thank you.
See the help for palette:
gnuplot> help set palette
After setting the palette, you give for example with points palette to the splot command.
Related
I am looking for a palette in gnuplot for red color from very-light-red to deep-red. I found a script for black here http://gnuplot.sourceforge.net/demo_5.3/pm3dcolors.16.gnu
I tried by changing set palette functions red, red, red in the above script, but it is not working.
By "legend" do you really mean "palette"? The legend is the list of plot titles and samples; entries there will normally appear in whatever color the corresponding plot used. The palette is the color gradient used for pm3d plots. To define a gradient from white to deep red:
set palette defined (0 "white", 1 "dark-red")
test palette
If you want more precise control over how light/dark the two extremes are you can provide instead hexadecimal descriptions of the RGB components. E.g. the above command is equivalent to
set palette defined (0 "0xffffff", 1 "0x8b0000")
I want to plot contour maps using Gnuplot.
I tried using the following command,
set palette rgbformulae 33,13,10
splot filename u 1:2:3
This is the image file I got using those commands.
But I want to give a white color scheme when the third column has a maximum value. How to do this?
There many, many options for palette choice. Without going into all of them, I suggest you try set palette cubehelix
That provides a color range from dark to white. Here is the output from
set palette cubehelix
test palette
I'm a novice in Gnuplot. Today I was plotting a simple txt file with two data columns, being the x and y coordinates of a cloud of points in the xy plane; I wanted to color them according to the position they occupied in the list, so I should have gone for something like:
plot "data.txt" u 1:2:0 lc palette
that produces what I want:
(desired plot)
By mistake, I omitted the "using" part of the command, so that I prompted:
plot "data.txt" lc palette
Now, the points still are plotted in the correct positions, so that gnuplot is automatically interpreting them as (x,y) coordinates... but the colors look like this:
(strangely colored plot)
I find this baffling since there's the possibility that I'm involuntarily highlighting some interesting feature of my data (which, by the way, consists of few iterations of a discrete recurrence for a set - the x=1.57 line you can see - of different initial conditions.
The question is: what criterion does 'lc palette' use to assign the parity I see to my points? What is its default behavior supposed to be in this case?
Thanks in advance!
EDIT: I don't know if it can be useful, but prompting 'show palette' I get:
palette is COLOR
rgb color mapping by rgbformulae are 7,5,15
figure is POSITIVE
all color formulae ARE NOT written into output postscript file
allocating ALL remaining color positions for discrete palette terminals
Color-Model: RGB
gamma is 1.5
I'm plotting data with the w labels modifier.
Is it possible to change the font size of these labels and/or rotate them?
I've been going through the documentation and can't find anything that'll do that.
There's set label rotate and set label font but those don't seem to apply a general rule for all labels.
Thanks.
Nevermind, I just realized I can add modifiers to the plots in this way:
plot "data" using 1:2:2 smooth frequency w labels rotate by 90 font "8"
OK, I think this is probably simple but I've searched extensively and can't find anything. What I want to do is specify the precise RGB colour values of a contour line generated with matplotlib. I know that if I do something like :
plt.contour(X,Y,Z,[0.1,0.2,0.3],colors='k')
then I'll get three contour levels which are all black, or if I were to substitute 'w' in place of 'k' then the contours would all be white. That's fine, but what I need to do is something like this :
plt.contour(X,Y,Z,[0.1,0.2,0.3],colors=(1.0,0.25,0.75)
Where the colours not chosen from some in-built presets but have RGB (or RGBA) values precisely defined by me.
Any ideas ?
You should give a list with colors. If the list is 1 color long, it will use that color for all contours.
plt.contour(X, Y, Z, [0.1,0.2,0.3], colors = [(1.0,0.25,0.75)])