Scatter Color Scale for Looping Script

Dear everyone,

I have some excel files. Each file containing some columns of parameter. I want to plot all of them in one graph with different color (let's say jet colormap).

Here is my code:

A       = dir('*.xlsx');
numprof = length(A); %number of profile
couleur = jet(numprof);

hold on; 
for nn = 1:numprof
    filename = A(nn).name; 
    data     = xlsread(filename); %
    a        = data(:,1);
    b        = data(:,2);

    % Plot
     scatter(lon(1),lat(1),'filled','color',couleur(nn,:)); % plot the first row value from each excel file
end

legend(compose("% d", 1:numprof),'Location','eastoutside');

This code produce this:

The scatter colors did not following jet colormap. Does anyone know the line I should add in this script?

best regards,

[Dyuman Joshi]

The behaviour/functionality of scatter() is different than plot().

To clarify, you are trying to plot the first pair of points from each file?

[Adi Purwandana]

Each file contains two columns. Let's start the loop for the 1st file... I want to plot the first row from both columns (from the 1st file off course), and let's say, this will be plotted as scatter blue (from the spectrum of jet). Then, move to the second file, I do the same and will be plotted as scatter as green... and so on... the last file will be plotted as red.

Answer 1

[Matthew Blomquist]

One option would be to store those values into an array within the for loop, and then plot the arrays with a colormap of jet after going through the loop. Something like:

A       = dir('*.xlsx');
numprof = length(A); %number of profile

figure() ;
hold on;

% Initialize
lon = zeros( numprof , 1 ) ;
lat = zeros( numprof , 1 ) ;

for nn = 1:numprof
    filename = A(nn).name;
    data = xlsread(filename); %
    lon(nn,1) = data(1,1);
    lat(nn,1) = data(1,2);
end

% For colorbar
c = 1 : numprof ;

% Plot
scatter(lon,lat,[],c,'filled');

colorbar
colormap jet

[Dyuman Joshi]

This is the way to go.

Once again, @Adi Purwandana, do not use xlsread. Use readmatrix instead.

[Adi Purwandana]

Thank you very much @Matthew Blomquist and @Dyuman Joshi. It works fine.

Here is my final codes:

clear all;
clc;

A       = dir('*.xlsx');
A       = natsortfiles(A);
numprof = length(A); %number of profile

hold on;
% Initialize
lon = zeros( numprof,1);
lat = zeros( numprof,1);
for nn = 1:numprof
    filename = A(nn).name;
    data = readmatrix(filename); %
    lon(nn,1) = data(1,1);
    lat(nn,1) = data(1,2);
end
% For colorbar
c = 1:numprof ;
% Plot
scatter(lon,lat,[],c,'filled');
colorbar
colormap jet

[Dyuman Joshi]

Looks good.