how can i read data given from a txt file and plot graph

How to read the data and plot graph from the data given.

Answer 1

[Erivelton Gualter]

You may check this other anser related to import data:

https://www.mathworks.com/matlabcentral/answers/460098-import-text-data-as-a-numeric-matrix-with-specific-delimiters

Also, I am attaching a code you might use:

%% Initialize variables.
filename = 'sound.txt';
delimiter = '\t';
startRow = 2;

%% Format for each line of text:
% For more information, see the TEXTSCAN documentation.
formatSpec = '%*s%f%f%f%f%f%f%f%f%[^\n\r]';

%% Open the text file.
fileID = fopen(filename,'r');

%% Read columns of data according to the format.
dataArray = textscan(fileID, formatSpec, 'Delimiter', delimiter, 'TextType', 'string', 'HeaderLines' ,startRow-1, 'ReturnOnError', false, 'EndOfLine', '\r\n');

%% Close the text file.
fclose(fileID);

%% Create output variable
sound = [dataArray{1:end-1}];
%% Clear temporary variables
clearvars filename delimiter startRow formatSpec fileID dataArray ans;

[X,Y] = meshgrid(-10:5:25, -15:5:100);
surf(X,Y,sound)
xlabel('X');
ylabel('Y');
zlabel('Sound');

[seelan kumar]

is there any other simpler coding that you can send me??Because i feel like ur coding is too long and its not in my syllabus.Tq

[Erivelton Gualter]

We can simpligy this as in the following.

startRow = 2;
fileID = fopen('sound.txt','r');
dataArray = textscan(fileID, '%*s%f%f%f%f%f%f%f%f%[^\n\r]', 'Delimiter', '\t', 'TextType', 'string', 'HeaderLines' ,1, 'ReturnOnError', false, 'EndOfLine', '\r\n');
fclose(fileID);

sound = [dataArray{1:end-1}];
[X,Y] = meshgrid(-10:5:25, -15:5:100);
surf(X,Y,sound)

Answer 2

[Star Strider]

If you have R2019a, use the readmatrix (link) function.

You are supposed to use the contour function for the plot.

EDIT —

D = readmatrix('sound.txt');
A = D(2:end,2:end);
X = D(2:end,1);
Y = D(1,2:end);

figure
contourf(X',Y,A', 'ShowText','on')
grid on
xlabel('X')
ylabel('Y')
colorbar