I have a data file that I plot using
plot 'data.dat' u 1:2 smooth csplines
and I want to reuse this function to get the ratio with another data file function. The x points for the two functions are different so I need to have the smoothed function with the entire information over any x-point to construct the ratio at an arbitrary x. Is possible to define the plotted smoothed function as a function over reals?
You can save the smoothed functions to an external file. You must make sure that both smoothed functions are interpolated over the same xrange and with the same number of samples:
set samples 500
set xrange [] writeback
set table 'data-smoothed.dat'
plot 'data.dat' using 1:2 smooth csplines
unset table
set xrange restore
set table 'data2-smoothed.dat'
plot 'data2.dat' using 1':2 smooth csplines
unset table
plot '< paste data-smoothed.dat data2-smoothed.dat' using 1:($4/$2)
If you're working on Windows, you may want to use the litte script paste.py shown in Get ratio from 2 files in gnuplot to merge the files.
Related
I'm not a dev, I'm doing this for a school project. I'm trying to put the following dataset into a surface plot in windows gnuplot. qt type terminal, if that's important.
https://files.catbox.moe/nbc6l1.json
As you can see, it's a huge set of data. Pulled directly from an image and into a csv file, which I converted to json.
When I type in "splot 'C:\Users\tyler\ESRP Data\sampleOutput.json'", this is what I get.
As you can see, there's only a single line, when there should be something approaching an intensity chart in a 3 dimensional space. Is it a problem with the data? Do I need a specific command to do this?
It would help if you attached an example of your image data to the question, and also if you provided a link to a plot similar to the one you are trying to create. There are many different styles one might use to represent a surface. I will attempt to guess at a possible solution.
Input image (scribbled in GIMP and saved as a png image):
Gnuplot surface plot:
set border -1
unset tics
# surface represented by colored lines in 3D
# down-sample by 4x in each dimension to get an interpretable surface
set palette defined (0 "blue", 1 "white")
splot 'scribble.png' binary filetype=png every 4:4:4 using 1:2:3:3 with lines lc palette
I have to "draw" a 3d function in gnuplot with the function sqrt(1-x**2+y**2), where the graph looks like a dome.
I am supposed to do it with unset parametric.
I just couldnt find out how to do it, any help would be appreciated.
First of all, your function sqrt(1-x**2+y**2) doesn’t represent the dome shape. The correct formula would be sqrt(1-(x**2+y**2)).
Then, even if you specify unset parametric, you can draw a dome shape by giving the function form to splot.
unset parametric
set xrange [-1.2:1.2]
set yrange [-1.2:1.2]
set isosamples 20,20
splot real(sqrt(1-(x**2+y**2))), sqrt(1-(x**2+y**2))
Many of the mathematical functions in gnuplot support complex numbers. sqrt(x) returns a complex number if x is negative. Note that such a value is treated like a missing value on a plot.
This script generates a figure like this (on pngcairo terminal).
I would like to prepare a script file to draw a 3D plot of some kinetic spectroscopy results. In the experiment the absorption spectrum of a solution is measured sequentially at increasing times from t0 to tf with a constant increase in time Δt.
The plot will show the variation of absorbamce (Z) with wavelength and time.
The data are recorded using a UV-VIS spectrometer and saved as a CSV text file.
The file contains a table in which the first column are the wavelengths of the spectra. Afterwards, a column is added for each the measured spectra, and a number of columns depends on the total time and the time interval between measuerments. The time for each spectra appears in the headers line.
I wonder if the data can be plotted directly witha minimum of preformatting and without the need to rewrite the data in a more estandar XYZ format.
The structure of the data file is something like this
Title; espectroscopia UV-Vis
Comment;
Date; 23/10/2018 16:41:12
Operator; laboratorios
System Name; Undefined
Wavelength (nm); 0 Min; 0,1 Min; 0,2 Min; 0,3 Min; ... 28,5 Min
400,5551; 1,491613E-03; 1,810312E-03; 2,01891E-03; ... 4,755786E-03
... ... ... ... ... ...
799,2119; -5,509266E-04; 3,26314E-04; -4,319865E-04; ... -5,087912E-04
(EOF)
A copy of a sample data is included in this file kinetic_spectroscopy.csv.
Thanks.
Your data is in an acceptable form for gnuplot, but persuading the program to plot this as one line per wavelength rather than a gridded surface is more difficult. First let's establish that the file can be read and plotted. The following commands should read in the x/y coordinates (x = first row, y = first column) and the z values to construct a surface.
DATA = 'espectros cinetica.csv'
set datafile separator ';' # csv file with semicolon
# Your data uses , as a decimal point.
set decimal locale # The program can handle this if your locale is correct.
show decimal # confirm this by inspecting the output from "show".
set title DATA
set ylabel "Wavelength"
set xlabel "Time (min)"
set xyplane 0
set style data lines
splot DATA matrix nonuniform using 1:2:3 lc palette
This actually looks OK with your data. For a smaller number of scans it is probably not what you would want. In order to plot separate lines, one per scan, we could break this up into a sequence of line plots rather than a single surface plot:
DATA = 'espectros cinetica.csv'
set datafile separator ";"
set decimal locale
unset key
set title DATA
set style data lines
set ylabel "Wavelength"
set xlabel "Time (min)"
set xtics offset 0,-1 # move labels away from axis
splot for [row=0:*] DATA matrix nonuniform every :::row::row using 1:2:3
This is what I get for the first 100 rows of your data file. The row data is colored sequentially by gnuplot linetypes. Other coloring schemes are possible.
Bit of a challenge here which I've been grappling with for some time. I'll explain my full work flow so you can reproduce if needed.
I'm creating virtual landscapes in Google SketchUp which I ultimately would like to use in Netlogo to examine how turtles interact with them.
My problem is that by the time I get the landscapes into Netlogo the units don't seem to relate to the original 3D model.
Step 1: Create simple hill on a 50m by 50m square in Sketchup using the Toposhaper extension.
Step 2: Export to .dae file and import into Meshlab, ensure the Meshlab model has the same dimensions as the Sketchup model by adjusting the units with the assistance of the measuring tool. Export from meshlab as .xyz file.
Step 3: Import .xyz file into QGis as points by adding a new layer from delimited file. Selecting field_1 and field_2 as X and Y fields.
Step 4: Create raster of points using Raster > Interpolation > Interpolation. Add field_3 as interpolation attribute, set number of columns to 50 by 50 (to correspond to the 50m x 50m 3D model), adjust cell size X and Y to match to ensure Netlogo will read the resulting .asc file.
Step 5: Finally, I setup a model in Netlogo to receive the raster. Firstly, in model settings I set the the min and max pxor and pycor to 0 and 50. Then, using the Gis Extension, I import the raster apply the z-value to a patch variable called elevation:
to load-gis
set elevation gis:load-dataset "cone_50.asc"
gis:set-world-envelope-ds gis:envelope-of elevation
gis:apply-raster elevation target-elev
end
Now, each patch of my 50 by 50 Netlogo world should have an elevation value taken from my 50 by 50 raster. In theory, adding all the elevation values together should (roughly) give me the total volume of the raised area of the hill? The figure I get is higher however and the problem gets worse with larger volumes.
Can anyone help?
For example , if I want to plot Sin(z) where z is a complex variable , how I will achieve it in either Octave or Maxima?
I don't know about Octave, but here is a message about that, with some code you can try in Maxima: https://www.ma.utexas.edu/pipermail/maxima/2007/006644.html
There may be more specific information for wxMaxima -- you can try their user forum: https://sourceforge.net/p/wxmaxima/discussion/435775/
(referring Octave 4.0.0)
How do you want to try to represent the output of the function? Plotting either the real or imaginary parts of the output can be done fairly simply using a 3-dimensional graph, where the x and y axes are the real and imaginary components of z, and the vertical axis is either the real or imaginary values of sin(z). Producing those are fairly simple in Octave. Here's a link to a script you can save and run to show an example.
Simply change the g = exp(f) line to g = sin(f).
Octave-help mailing list example
Note that the imaginary part plot is commented out. Just switch the # between the different plot commands if you want to see that part.
Now, are you instead looking for options to map the Z plane (z=x+iy) to the W plane (w=u+iv) and represent closed contours mapped by w=sin(z)? in that case you'll need to do parametric plotting as described on this FIT site. There is a link to his Matlab program at the bottom of the explanation that provides one method of using color coding to match z->w plane contour mapping.
Those m-files are written for Matlab, so a few things do not work, but the basic plotting is compatible with Octave 4.0.0. (the top level ss13.m file will fail on calls to flops and imwrite)
But, if you put your desired function in myfun13.m for f, df and d2f, (sin(z), cos(z), -sin(z) respectively), then run cvplot13, you'll get color maps showing the correspondence between z and w planes.
wxMaxima has a plot3d that can do it. Since the expression to plot is in terms of x and y, I plotted the function's magnitude with abs(f(x+%i*y)):
plot3d(abs((x+%i*y-3)*(x+%i*y-5)*(x+%i*y-6)), [x,2,7], [y,-1,1], [grid,100,100], [z,0,5])$