How I can create a movie from a bunch of plots - matlab

I am really a beginner to make a movie. I need to make a movie from a bunch of plots. How I can make it.
I have 8 plots , which are y versus x. I want to make movie based on x to see how y change with increasing x.
Please consider my matlab file is as below:
x=[1 1.2 1.4 2 3 4 5 7 9 10];
y1=[2.8 7.6 10.9 12.3 15.0 21 12.3 14.5 42.4 47.7];
y2=1e8.*[0.599e-7 0.607e-7 0.343e-7 0.3e-7 0.873e-8 0.578e-8 0.298e-8 0.725e-9 0.14e-8 0.478e-9];
y3=10.*[0.136 0.544 0.834 1.03 0.366 0.314 0.703 0.207 0.696 0.164];
y4=10.*[0.26 0.21 0.17 0.25 0.31 0.34 0.16 0.15 0.13 0.31];
y5=....
y6=...
y7=...
y8=[6 7.6 10.9 12.3 15.0 21 12.3 19.5 42.4 47.7 ];
plot(x,y1)
hold on
plot(x,y2)
hold on
plot(x,y3)
hold on
plot(x,y4)
hold on
plot(x,y5)
hold on
plot(x,y6)
hold on
...
plot(x,y8)
I wrote following as a simple example but it does not work:
clc;clear all;
x=[1 1.2 1.4 2 3 4 5 7 9 10];
y = zeros(4,10);
y(1,:)=[2.8 7.6 10.9 12.3 15.0 21 12.3 14.5 42.4 47.7 ];
y(2,:)=1e8.*[0.599e-7 0.607e-7 0.343e-7 0.3e-7 0.873e-8 0.578e-8 0.298e-8 0.725e-9 0.14e-8 0.478e-9];
y(3,:)=10.*[0.136 0.544 0.834 1.03 0.366 0.314 0.703 0.207 0.696 0.164 ];
y(4,:)=10.*[0.26 0.21 0.17 0.25 0.31 0.34 0.16 0.15 0.13 0.31 ];
figure;
hold on
for n = 1:10
plot(x,y)
M(n)=getframe; % get frame from the current figure;
end
movie(M,10); %plays movie M 10 times
In a nut shell , How I can make a movie like Fig. 3.2: in the following link

The basic code for making a movie from a given figure is like this:
figure;
hold on
for n = 1:20
plot(1:10,n*(1:10))
M(n)=getframe; % get frame from the current figure;
end
movie(M,10); %plays movie M 10 times
Look into the help files for getframe and movie to see what other options are available. To save a movie out, see movie2avi.
Note that for a given figure you only need to call hold on once. If all your y values are of the same length, then you can re-write your code/plotting more efficiently like this:
x=[1 1.2 1.4 2 3 4 5 7 9 10];
y = zeros(8,10);
% then this for each of your sets of y values
y(1,:) = [2.8 7.6 10.9 12.3 15.0 21 12.3 14.5 42.4 47.7 53 81.3 86.1];
...
y(8,:)=[6 7.6 10.9 12.3 15.0 21 12.3 19.5 42.4 47.7 53 81.3 86.1 ];
plot(x,y) % plots all the y's against x with automatic coloring
plot(x,y(n,:)) % plots just one set of y values against x

Related

Octave - why is surf not working but trisurf does?

I am able to plot a trisurf chart, but surf does not work.
What am I doing wrong?
pkg load statistics;
figure (1,'name','Matrix Map');
colormap('hot');
t = dlmread('C:\Map3D.csv');
tx =t(:,1);ty=t(:,2);tz=t(:,3);
tri = delaunay(tx,ty);
handle = surf(tx,ty,tz); #This does NOT work
#handle = trisurf(tri,tx,ty,tz); #This does work
`error: surface: rows (Z) must be the same as length (Y) and columns (Z) must be the same as length
(X)
My data is in a CSV (commas not shown here)
1 2 -0.32
2 2 0.33
3 2 0.39
4 2 0.09
5 2 0.14
1 2.5 -0.19
2 2.5 0.13
3 2.5 0.15
4 2.5 0.24
5 2.5 0.33
1 3 0.06
2 3 0.44
3 3 0.36
4 3 0.45
5 3 0.51
1 3.5 0.72
2 3.5 0.79
3 3.5 0.98
4 3.5 0.47
5 3.5 0.55
1 4 0.61
2 4 0.13
3 4 0.44
4 4 0.47
5 4 0.58
1 4.5 0.85
surf error message is different in Matlab or in Octave.
Error message from Matlab:
Z must be a matrix, not a scalar or vector.
The problem is pretty clear here since you specified Z (for you tz) as a vector.
Error message from Octave:
surface: rows (Z) must be the same as length (Y) and columns (Z) must be the same as length (X)
You are wrong here since on your example, columns (Z) = 1, but length (X) = 26, so here is the mistake.
One of the consequences of that is that with surf you cannot have "holes" or undefined points on your grid. On your case you have a X-grid from 1 to 5 and a Y-grid from 2 to 4.5 but point of coordinate (2, 4.5) is not defined.
#Luis Mendo, Matlab and Octave do allow the prototype surf(matrix_x, matrix_y, matrix_z) but the third argument matrix_z still have to be a matrix (not a scalar or vector). Apparently, a matrix of only one line or column is not considered as a matrix.
To solve the issue, I suggest something like:
tx = 1:5; % tx is a vector of length 5
ty = 2:0.5:4.5; % ty is a vector of length 6
tz = [-0.32 0.33 0.39 0.09 0.14;
-0.19 0.13 0.15 0.24 0.33;
0.06 0.44 0.36 0.45 0.51;
0.72 0.79 0.98 0.47 0.55;
0.61 0.13 0.44 0.47 0.58;
0.85 0. 0. 0. 0.]; % tz is a matrix of size 6*5
surf(tx,ty,tz);
Note that I had to invent some values at the points where your grid was not defined, I put 0. but you can change it with the value you prefer.

Editing distance between tick marks

I am currently using subplots in MATLAB and this is my x tick mark data:[.4 .5 .6 .9 1.2 1.5 2 2.5 3 4 5 6 7 8 9 10 12 15 20 30 40]
I am trying to determine if there is a way to space the tick marks evenly, or expand the spacing for the lower values so you can actually read the numbers. In short I would like the physical spacing of the tick marks to be based on some predetermined constant and not the actual numerical values.
You could use logarythmic scale for x-axis - use semilogx instead of plot.(IMO this would be better in your case)
x = [.4 .5 .6 .9 1.2 1.5 2 2.5 3 4 5 6 7 8 9 10 12 15 20 30 40];
y = x/2; % some example data
figure
semilogx(x,y, '.')
set(gca,'xtick', x)
Another option is to change labels on x-ticks setting xticklabel property. Note that you can set custom values in ticks vector.
x = [.4 .5 .6 .9 1.2 1.5 2 2.5 3 4 5 6 7 8 9 10 12 15 20 30 40];
y = x/2; % some example data
ticks = [];
for t = 1:size(x,2)
ticks = [ticks t];
end
figure
plot(ticks, y, '.') % in this example same as 'plot(y)'
set(gca, 'xtick', ticks,'xticklabel', {.4 .5 .6 .9 1.2 1.5 2 2.5 3 4 5 6 7 8 9 10 12 15 20 30 40})

Inconsistent dimension error when plotting mesh in Matlab

I'm new to Matlab and I want to plot a mesh. My coordinates are:
x = [30 34 38 40 44 48 50]
y = [1:5:20]
Z = [9.1 8.5 7.83 7.54 7.07 6.61 6.49 ;
14.5 8.96 8.21 7.71 7.07 6.61 6.4;
13.37 13.4 10.2 9.4 9 7.3 7.9;
12.09 12 12.14 11.96 13.58 14.12 14.311;
14.97 10.77 11.87 12.4 13.62 14.19 14.94]
Ehen I tried to plot it in Matlab it gives following error:
Data point coordinates have inconsistent dimension.
You have indeed inconsistent dimensions as you need 5 elements in y. Also you need a matrix Z, not a vector.
The following should get you starting:
y = [0:5:20]
%// reshape z in case z is a vector
z = reshape(Z,numel(y),numel(x))
figure(1)
%// mesh(x,y,z)
surf(x,y,z) % colored mesh
Check the data sizes and adjust the reshaping according to your needs!
In general, if X and Y are vectors, length(X) = n and length(Y) = m, where `[m,n] = size(Z)v.
In your case:
length(x)
7
length(y)
4
but
size(Z)
1 35
So you need to reshape the Z.
Do:
x = [30 34 38 40 44 48 50]
y = [0:5:20]
Z = [9.1 8.5 7.83 7.54 7.07 6.61 6.49 ; 14.5 8.96 8.21 7.71 7.07 6.61 6.4; 13.37 13.4 10.2 9.4 9 7.3 7.9; 12.09 12 12.14 11.96 13.58 14.12 14.311; 14.97 10.77 11.87 12.4 13.62 14.19 14.94]
Z = reshape(Z,numel(y),numel(x))
mesh(x,y,Z)

Smooth data and graph in MATLAB [duplicate]

Using MATLAB, I have a matrix (data) and am plotting using imagesc(data) to produce a heatmap:
data = [1 1 1 1 1 1 1 1 1 1; 1 1.04 1.04 1.04 1.03 1 1.01 1.01 1.03 1.01; 1.36 1.3 1.25 1.2 1.15 1.1 1.2 1.13 1.07 1.11; 3.65 3.16 2.94 2.68 2.39 2.22 2.17 1.95 1.79 1.81; 5.91 5.75 5.47 5.3 4.98 4.79 4.62 4.55 4.38 4.19; 6 6 5.99 5.83 5.49 5.33 5.14 4.94 4.77 4.74];
imagesc(data)
Is there a way to 'smooth' the pixels in order to produce something more like this:
interp2 may be of use here. Use the data as key points, then create a finer grid of points that span the same width and height and interpolate in between the key points.
Something like this:
%// Define your data
data = [1 1 1 1 1 1 1 1 1 1; 1 1.04 1.04 1.04 1.03 1 1.01 1.01 1.03 1.01; 1.36 1.3 1.25 1.2 1.15 1.1 1.2 1.13 1.07 1.11; 3.65 3.16 2.94 2.68 2.39 2.22 2.17 1.95 1.79 1.81; 5.91 5.75 5.47 5.3 4.98 4.79 4.62 4.55 4.38 4.19; 6 6 5.99 5.83 5.49 5.33 5.14 4.94 4.77 4.74];
%// Define integer grid of coordinates for the above data
[X,Y] = meshgrid(1:size(data,2), 1:size(data,1));
%// Define a finer grid of points
[X2,Y2] = meshgrid(1:0.01:size(data,2), 1:0.01:size(data,1));
%// Interpolate the data and show the output
outData = interp2(X, Y, data, X2, Y2, 'linear');
imagesc(outData);
%// Cosmetic changes for the axes
set(gca, 'XTick', linspace(1,size(X2,2),size(X,2)));
set(gca, 'YTick', linspace(1,size(X2,1),size(X,1)));
set(gca, 'XTickLabel', 1:size(X,2));
set(gca, 'YTickLabel', 1:size(X,1));
%// Add colour bar
colorbar;
The code that's at the bottom is required because defining the finer grid ultimately increases the size of the image. I need to relabel the axes to go back to the original size.
We get this:
Small Note
I'm using MATLAB R2014a, and the default colour map is jet. You're using R2014b+ and the default colour map is parula. You won't get the same colour distribution as me, but you will get the smoothness you desire.
You can also use the pcolor(data) function with shading interp to make the color resolution smooth. No need to interpolate the data before plotting.

Selecting elements from a matrix in matlab

I have a matrix which is 36 x 2, but I want to seperate the elements to give me 18, 2 x 2 matrices from top to bottom. E.g. if I have a matrix:
1 2
3 4
5 6
7 8
9 10
11 12
13 14
... ...
I want to split it into seperate matrices:
M1 = 1 2
3 4
M2 = 5 6
7 8
M3 = 9 10
11 12
..etc.
maybe the following sample code could useful:
a=rand(36,2);
b=reshape(a,2,2,18)
then with the 3rd index of b you can access your 18 2x2 matrices, eg. b(:,:,2) gives the second 2x2 matrix.
I think that the direct answer to your question is:
sampledata = [...
0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10 0.11 0.12 0.13 0.14 0.15 0.16 0.17 0.18 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18; ...
0.19 0.20 0.21 0.22 0.23 0.24 0.25 0.26 0.27 0.28 0.29 0.30 0.31 0.32 0.33 0.34 0.35 0.36 1.19 1.20 1.21 1.22 1.23 1.24 1.25 1.26 1.27 1.28 1.29 1.30 1.31 1.32 1.33 1.34 1.35 1.36];
for ix = 1:(size(sampledata,2)/2)
assignin('base',['M' sprintf('%02d',ix)], sampledata(:,ix*2+[-1 0]))
end
This creates 18 variables, named 'M01' through 'M18', with pieces of the sampledata matrix.
However, please don't use dynamic variable names like this. It will complicate every other piece of code that it touches. Use a cell array, a 3D array (as suggested by #Johannes_Endres +1 BTW), or structure. Anything that removes the need for you to write something like this later on:
%PLEASE DO NOT USE THIS
%ALSO DO NOT BACK YOURSELF INTO A CORNER WHERE YOU HAVE TO DO IT IN THE FUTURE
varNames = who('M*');
for ix = 1:length(varNames )
str = ['result(' num2str(ix) ') = some_function(' varNames {ix} ');'];
eval(str);
end
I've seen code like this, and it is slow and extremely cumbersome to maintain, not to mention the headache and pain to your internal beauty-meter.
x = reshape(1:36*2,[2 36])'
k = 1
for i = 1:2:35
eval(sprintf('M%d = x(%d:%d,:);',k,i,i+1));
k = k+1;
end