How to draw the contour lines in MATLAB.

Can any any one help me how to draw the contour lines in MATLAB. I have data in Excel. i Need to draw contour lines for 0.1, 0.2 till 1.

Answer 1

[Walter Roberson]

data = readmatrix('Sai.xlsx');
contour(data, 0.1:0.1:1)
colorbar

[SARVESH R]

sir getting this error.

Undefined function 'readmatrix' for input arguments of type 'char'.

Error in Contour (line 5)

data = readmatrix('Sai.xlsx');

[Walter Roberson]

tbl = readtable('Sai.xlsx', 'readvariablenames', false);
data = tbl{:,:} ;
contour(data, 0.1:0.1:1)
colorbar

Next time please fill in the Release field when creating the question so that people do not waste time giving you solutions that cannot be used in your older software.

[SARVESH R]

thank you very much sir. its working. sir is it possible to give the lables on the line i am using R2014aversion

[Walter Roberson]

To label the contours see clabel() https://www.mathworks.com/help/matlab/ref/clabel.html

Answer 2

[Benjamin Kraus]

The answer depends in part on how the data is formatted in Excel, but something like this should get you started (see attached spreadsheet):

tbl = readtable('Peaks.xlsx');
contour(tbl.Variables,0.1:0.1:1);

[SARVESH R]

I tried but uable to draw the contours. could you pls help me sir. I am attaching the sample speed sheet. thank you sir

[Walter Roberson]

You have 19 rows and 73 columns. What do you want to draw the contours between?

[Benjamin Kraus]

If you replace Peaks.xlsx with Sai.xlsx, my example code seems to work fine on your data.

tbl = readtable('Sai.xlsx');
contour(tbl.Variables,0.1:0.1:1);

If you ran into some issue with that code, could you give more detail? For example, what error messages did you get? Did the picture not look like you expected?

[SARVESH R]

Sir i got an error like this

Warning: Variable names were modified to make them valid MATLAB identifiers.

> In makeValidName at 25

In @table\private\setVarNames at 48

In table.readXLSFile at 113

In table.readFromFile at 35

In readtable at 118

In Contour at 2

Error using table/subsrefDot (line 76)

Unrecognized variable name 'variables'.

Error in table/subsref (line 62)

[varargout{1:nargout}] = subsrefDot(t,s);

Error in Contour (line 6)

contour(tbl.variables,0.1:0.1:1)

Answer 3

[SARVESH R]

Sir i would like to draw the contour lines for 0.9, 0.8,0.7, 0.6,0.5,0.4,0.3,0.2 and 0.1