I plot a 2D function using splot with a colour palette:
set zrange [0.5:1.5]
set palette defined ( 0 "green", 1 "black", 2 "red" )
splot "HTSG_PeakPositions_thetaI080.gnuplot" using 3:1:5 title 'Relative Peak Positions' with pm3d
This somehow works; however, I'd like the graph to be black exactly at value 1.0 and coloured appropriately if it diverges from this level. The problem is that the palette is defined relatively to the range of min:max values contained in the plot and not to absolute values. The zrange option doesn't seem to affect this behaviour. Is there a way to create the absolute mapping?
The color range is affected by set cbrange:
set cbrange [0.5:1.5]
set palette defined ( 0 "green", 1 "black", 2 "red" )
splot "HTSG_PeakPositions_thetaI080.gnuplot" using 3:1:5 title 'Relative Peak Positions' with pm3d
If you want some kind of autoscaling symmetric to 1.0, you can use the stats command to determine the color range before plotting:
stats "HTSG_PeakPositions_thetaI080.gnuplot" using 5 nooutput
cb_val = (abs(STATS_min - 1) < abs(STATS_max - 1) ? abs(STATS_max - 1) : abs(STATS_min - 1))
set cbrange [1 - cb_val : 1 + cb_val]
Related
I am trying to visualize a time series data set on one plot as a pseudo 3d figure. However, I am having some trouble getting the filledcurves capability working properly. It seems to be adding an unwanted border at the "bottom" of my functions and I do not know how to fix this.
This is my current set up: I have nb_of_frames different files that I want to plot on one figure. Without the filledcurves option, I can do something like this
plot for [i=1:nb_of_frames] filename(i) u ($1):(50.0 * $2 + (11.0 - (i-1)*time_step)) w l linewidth 1.2 lt rgb "black" notitle
which produces a figure like this:
no fill options
Instead of doing this, I want to use the filledcurves option to bring my plots "forward" and highlight the function that is more "forward" which I try to do with:
plot for [i=1:nb_of_frames] filename(i) u ($1):(50. * $2 + (11. - (i-1)*time_step)) w filledcurves fc "white" fs solid 1.0 border lc "black" notitle
This produces a figure as follows:
This is very close to what I want, but it seems that the border option adds a line underneath the function which I do not want. I have tried several variants of with filledcurves y1=0.0 with different values of y1, but nothing seems to work.
Any help would be appreciated. Thank you for your time.
Here is another workaround for gnuplot 5.2.
Apparently, gnuplot closes the filled area from the last point back to the first point. Hence, if you specifiy border, then this line will also have a border which is undesired here (at least until gnuplot 5.4rc2 as #Ethan says).
A straightforward solution would be to plot the data with filledcurves without border and then again with lines. However, since this is a series of shifted data, this has to be plotted alternately. Unfortunately, gnuplot cannot switch plotting styles within a for loop (at least I don't know how). As a workaround for this, you have to build your plot command in a previous loop and use it with a macro # (check help macros) in the plot command. I hope you can adapt the example below to your needs.
Code:
### filledcurves without bottom border
reset session
set colorsequence classic
$Data <<EOD
1 0
2 1
3 2
4 1
5 4
6 5
7 2
8 1
9 0
EOD
myData(i) = sprintf('$Data u ($1-0.1*%d):($2+%d/5.)',i,i)
myFill = ' w filledcurves fc "0xffdddd" fs solid 1 notitle'
myLine = ' w l lc rgb "black" notitle'
myPlotCmd = ''
do for [i=11:1:-1] {
myPlotCmd = myPlotCmd.myData(i).myFill.", ".myData(i).myLine.", "
}
plot #myPlotCmd
### end of code
Result:
I can reproduce this in gnuplot 5.2.8 but not in the output from the release candidate for version 5.4. So I think that some bug-fix or change was applied during the past year or so. I realize that doesn't help while you are using verion 5.2, but if you can download and build from source for the 5.4 release candidate that would take care of it.
Update
I thought of a work-around, although it may be too complicated to be worth it.
You can treat this as a 2D projection of a 3D fence plot constructed using plot style with zerrorfill. In this projection the y coordinate is the visual depth. X is X. Three quantities are needed on z: the bounding line, the bottom, and the top. I.e. 5 fields in the using clause: x depth zline zbase ztop.
unset key
set view 90, 180
set xyplane at 0
unset ytics
set title "3D projection into the xz plane\nplot with zerrorfill" offset 0,-2
set xlabel "X axis" offset 0,-1
set zlabel "Z"
splot for [i=1:25] 'foo.dat' using ($1+i):(i/100.):($2-i):(-i):($2-i) \
with zerrorfill fc "light-cyan" lc "black" lw 2
I have a problem where all images have the same object; however, these objects can either have number_of_colors<=3 OR number_of_colors>3 and images are not labeled.
My attempt starts by converting RGB to LAB and Consider only the A & B to find the color coverage of that image. I was thinking of it as an area on the AB space. So for every image, I found the range of A and B (i.e max(A)-min(A), max(B)-min(B)) and multiplied them together to get the area, assuming it's a rectangle. Then I threshold using this feature.
Please let me know if intuition is correct and why it isn't working. Here is the confusion matrix:
TP: 0.41935483871, FN: 0.0645161290323
FP: 0.0967741935484, TN: 0.41935483871
Here is the basic routine the should work per image
LAB = rgb_to_lab(data_rgb[...,0],data_rgb[...,1],data_rgb[...,2])
A = LAB[1]
B = LAB[2]
minA,maxA = np.min(A),np.max(A)
minB,maxB = np.min(B),np.max(B)
diff_A = maxA - minA
diff_B = maxB - minB
area = diff_A * diff_B
# p is the normalized area
p = area/(200*200.)
# Found 0.53 to be the best possible threshold
if p >0.53:
print 'class 1 - colors > 3'
else:
print 'class 2 - colors <= 3'
Edit 1:
Here is an image to show how the threshold separates positive and negative images
Edit 2:
This shows the same plot but only considering A and B values with luminance between 16 and 70 which seems to increase the area of separation reduces the FP by 1.
I'm now trying to use filledcurve in gnuplot 4.6, patchlevel 1. Following shows the sample script:
set term epslatex
set output "figure.tex"
set xlabel "\\huge{x-axis}"
set ylabel "\\huge{y-axis}"
set format xy "\\LARGE{%.0f}"
set xrange [0.0:10.0]
set yrange [0.0:100.0]
set xtics 2.0
set ytics 20.0
set xtics offset 0, -0.3
f1(x) = x**1
f2(x) = x**2
f3(x) = x**3
set nokey
plot '+' using 1:(f2($1)):(f3($1)) with filledcurve lt 1 lc rgb "gray60",\
'+' using 1:(f1($1)):(f2($1)) with filledcurve lt 1 lc rgb "gray40",\
'+' using 1:(0.0):(f1($1)) with filledcurve lt 1 lc rgb "gray20"
I don't known why, but it seems that there are white annoying slits between bars. It cannot be get rid of even if I increase the number of set samples.
Is there any idea to remove these slits?
Unfortunately, this is a viewer problem related to the drawing of adjacent filled polygons, see also problematic Moire pattern in image produced with gnuplot pm3d and pdf output or the bug report #1259 cairolatex pdf fill patterns.
In your case you can use a workaround:
When you have only two columns in the using statement, the area is drawn as closed polygon and doesn't show these artifacts (filledcurves closed). So you must fill the area between each curve and the x1 axis (with filledcurves x1).
Because of a bug in the clipping of curves which exceed the y-range, you must do the clipping of the f3 curve yourself (i.e. use f3($1) > 100 ? 100 : f3($1)). This bug is fixed in the development version.
So you script is:
set term epslatex standalone
set output "figure.tex"
set xlabel "\\huge x-axis"
set ylabel "\\huge y-axis"
set format xy "\\LARGE %.0f"
set xrange [0.0:10.0]
set yrange [0.0:100.0]
set xtics 2.0
set ytics 20.0
set xtics offset 0, -0.3
f1(x) = x**1
f2(x) = x**2
f3(x) = x**3
set nokey
plot '+' using 1:(f3($1) > 100 ? 100 : f3($1)) with filledcurve x1 lt 1 lc rgb "gray60",\
'+' using 1:(f2($1)) with filledcurve x1 lt 1 lc rgb "gray40",\
'+' using 1:(f1($1)) with filledcurve x1 lt 1 lc rgb "gray20"
set output
system('latex figure.tex && dvips figure.dvi && ps2pdf figure.ps')
with the result (using 4.6.1):
Note also, that LaTeX commands like \huge don't take arguments, but are switches. Test e.g. \huge{A}BC, this will make all letter huge. Usually you must limit the scope of \huge with brackets like {\huge ABC}, but if the whole label is affected, it is enough to use set xlabel "\\huge x-axis". That doesn't change anything in your case, but may give you troubles in other circumstances :)
Would anyone know how to specify a ColorMatrix (Specifically a System::Drawing::Imaging::ColorMatrix in C++/CLI) to set an alpha threshold? For example if I were to use 10 (10/255) as my threshold then any pixel with an RGBA Alpha of 10 or less would have 0.0f Alpha and every pixel above would get 1.0f.
I'm trying to implement ColorID picking in a 2D scene editor as I'm sick of using my current unwieldy method of reversing my drawing transformations to determine which pixel of a given bitmap the mouse is pointing at. So what I want to do instead is do a ColorID rendering pass like in OpenGL as described here http://content.gpwiki.org/index.php/OpenGL_Selection_Using_Unique_Color_IDs However I can't just compare the locations of bitmaps onscreen as most of them include tons of white-space that I don't want being picked up by mouse picking which leaves me with color-picking.
For now my ColorMatrix looks like
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 1 0
R G B 0 1
following Hans' answer to GDI+: Set all pixels to given color while retaining existing alpha value but I'd like it to also apply a threshold to the Alpha component (provided that's even possible using a ColorMatrix)
Maybe you're looking for the ImageAttributes.SetThreshold method.
My data file has four columns because opencv saves elements in an n x 4 form in xml when exporting a cv::Mat to xml.
How can I concatenate these four columns into one?
reset
set terminal postscript eps enhanced
set output 'imp.eps'
set pm3d
set palette model HSV defined ( 0 0 1 1, 1 1 1 1 )
set style data histogram
set colorbox user
set origin 0.0,0.10
set size ratio 0 1,0.8
set colorbox horizontal origin graph 0.0, -0.15, 0 size graph 1, 0.05, 0 noborder
set xrange [0:4096]
plot 'var_imp_first_run.data' using 1
set output
I have 4094 elements, and this example creates an histogram where the first 1024 is plotted. I need to append column 2 from x=1024:2048. Please ignore the colorbox stuff; I'm just playing around to learn gnuplot.
I found out that following solve my problem above.
set xrange [0:4096]
plot newhistogram at 0, 'var_imp_first_run.data' every:: 7 using 1,\
newhistogram at 1024,'var_imp_first_run.data' every:: 7 using 2,\
newhistogram at 2048,'var_imp_first_run.data' every:: 7 using 3,\
newhistogram at 3072,'var_imp_first_run.data' every:: 7 using 4;
Then I found out that it was not what I wanted, because the data are arranged as entries,
x1,x2,x3,x4
x5,x6,x7,x8
and so on.
So what I really need is a histogram that plots the rows before columns. Is it possible?
If you want it to read
x1
x2
x3
instead of
x1,x2,x3
Then (assuming you are on *nix) use
plot 'cat var_imp_first_run.data | tr "," "\n" |' using 1
This is calling the following command and reading the output via the pipe at the end:
cat var_imp_first_run.data | tr "," "\n"
Here, tr is just transcribing commas as newlines.