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How to plot from txt file using textscan?

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Md Golam Sarwar
Md Golam Sarwar on 11 Oct 2020
Commented: Md Golam Sarwar on 11 Oct 2020
XFOIL Version 6.99
Calculated polar for: NACA 2408
1 1 Reynolds number fixed Mach number fixed
xtrf = 1.000 (top) 1.000 (bottom)
Mach = 0.000 Re = 9.000 e 6 Ncrit = 9.000
alpha CL CD CDp CM Top_Xtr Bot_Xtr
------ -------- --------- --------- -------- -------- --------
0.000 0.2388 0.00480 0.00041 -0.0529 0.4528 0.2191
1.000 0.3512 0.00477 0.00048 -0.0532 0.3796 0.3528
2.000 0.4613 0.00494 0.00072 -0.0533 0.2523 0.5660
4.000 0.6729 0.00562 0.00159 -0.0513 0.0456 0.9816
5.000 0.7881 0.00625 0.00207 -0.0524 0.0199 1.0000
6.000 0.8975 0.00690 0.00262 -0.0521 0.0110 1.0000
7.000 1.0060 0.00760 0.00326 -0.0518 0.0076 1.0000
8.000 1.1129 0.00842 0.00404 -0.0513 0.0053 1.0000
9.000 1.2181 0.00931 0.00492 -0.0506 0.0044 1.0000
11.000 1.4217 0.01152 0.00716 -0.0484 0.0032 1.0000
12.000 1.5182 0.01294 0.00863 -0.0467 0.0027 1.0000
13.000 1.6086 0.01477 0.01056 -0.0441 0.0022 1.0000

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Md Golam Sarwar
Md Golam Sarwar on 11 Oct 2020
I need to plot alpha vs CL, CL vs CD etc.
I am getting this following
Var1 Var2 Var3 Var4 Var5 Var6 Var7 Var8 Var9 Var10 Var11
____ ______ _______ _______ _______ ______ ______ ____ _______ _____ _____
NaN NaN 1 NaN 1 NaN NaN NaN '' '' NaN
NaN NaN 0 NaN NaN 9 NaN 6 'Ncrit' '=' 9
NaN NaN NaN NaN NaN NaN NaN NaN '' '' NaN
NaN NaN NaN NaN NaN NaN NaN NaN '' '' NaN
NaN NaN NaN NaN NaN NaN NaN NaN '' '' NaN
0 0.2388 0.0048 0.00041 -0.0529 0.4528 0.2191 NaN '' '' NaN
1 0.3512 0.00477 0.00048 -0.0532 0.3796 0.3528 NaN '' '' NaN
2 0.4613 0.00494 0.00072 -0.0533 0.2523 0.566 NaN '' '' NaN
4 0.6729 0.00562 0.00159 -0.0513 0.0456 0.9816 NaN '' '' NaN
5 0.7881 0.00625 0.00207 -0.0524 0.0199 1 NaN '' '' NaN
6 0.8975 0.0069 0.00262 -0.0521 0.011 1 NaN '' '' NaN
7 1.006 0.0076 0.00326 -0.0518 0.0076 1 NaN '' '' NaN
8 1.1129 0.00842 0.00404 -0.0513 0.0053 1 NaN '' '' NaN
9 1.2181 0.00931 0.00492 -0.0506 0.0044 1 NaN '' '' NaN
11 1.4217 0.01152 0.00716 -0.0484 0.0032 1 NaN '' '' NaN
12 1.5182 0.01294 0.00863 -0.0467 0.0027 1 NaN '' '' NaN
13 1.6086 0.01477 0.01056 -0.0441 0.0022 1 NaN '' '' NaN
Walter Roberson
Walter Roberson on 11 Oct 2020
You could probably add a 'HeaderLines' option to the detectImportOptions. I think it might be 'HeaderLines', 9
Md Golam Sarwar
Md Golam Sarwar on 11 Oct 2020
Thanks! it works
filename = 'Save_Polar.txt';
opt = detectImportOptions(filename);
data = readtable(filename, opt);
D=data(6:end,1:5);
Alpha =D{:,1};
CL =D{:,2};
CD =D{:,3};
CDp =D{:,4};
CM =D{:,5};

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Answers (1)

Paul
Paul on 11 Oct 2020
I’ve been having a lot of success lately in these types of problems by using extractFileText to read it all into a string, and then using a few manipulations to get to the data. Works well if you have a well-defined file format.

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