How to retrieve data from a Excel sheet saved at a particular location in pc?

Hello,

I want to retrieve data from an excel sheet stored at a particular location in the pc, the path of that particular file is provided in the code as below. However, the code is unable to read the file from the given location. I tried the matlab command importdata as well as readmatrix.

sigma_diff=0.5;
beta=0.01;
gamma_nonlin=2*beta;


i=100;
j=1;
speed_F=zeros(i,j);

for j=1:100
    mu(i,j)=importdata('D:\Rahul\Data_tokamak\data&plot\data1_non-ctrw\L-mode data from L-mode eqn\data without edge source\Fisher model\data1_L0_sig0.5_f1\a5_term(i,j)'); 
    speed_F(i,j)=sqrt(sigma_diff*data1.variable.turbulence(i,j)*mu(i,j)^2)/(2*gamma_nonlin);
end

Error using importdata
Unable to open file.

Answer 1

[Chunru]

You need to provide the extension name (.xlsx ?) to the file.

[Dyuman Joshi]

Also, use readmatrix() over importdata().

Note that readmatrix() will read all the data (in the specified range in a given sheet) at once, you will not need a for loop for that.

[Rahul]

ok. Will do that.

But it still not able to read the file. I used the extension .mat as it is a matlab generated file.

rgds

[Chunru]

Matlab can generate different file types. If Matlab generate .xlsx file, you have to specify it as .xlsx file.

There are a number of ways to read in data: readtable, readmatrix, importdata, ...

[Dyuman Joshi]

"I used the extension .mat as it is a matlab generated file."

It does not matter how the file is generated, you have to provide the extension that is at the end of the file name.

[Rahul]

hi,

now the code can detect the file but can't read the sub-file and its data (probably)

as it gives the error

Unable to resolve the name 'data1.variable.turbulence'.

Error in turb_speed (line 16)

speed_F(i,j)=sqrt(sigma_diff*data1.variable.turbulence(i,j)*mu_lmode^2)/(2*gamma_nonlin);

Here, I've attached the code as well as the data also. kindly advise.

clc;
clear all;


sigma_diff=0.5;
beta=0.01;
gamma_nonlin=2*beta;


i=100;
j=1;
speed_F=zeros(i,j);
mu_lmode=importdata('D:\Rahul\Data_tokamak\data&plot\data1_non-ctrw\L-mode data from L-mode eqn\data without edge source\Fisher model\data1.mat');

for j=1:100
    speed_F(i,j)=sqrt(sigma_diff*data1.variable.turbulence(i,j)*mu_lmode^2)/(2*gamma_nonlin);
end
   

[Stephen23]

Avoid IMPORTDATA.

Use LOAD for MAT files:

F = './data1.mat';
S = load(F)

S = struct with fields:
    data: [1×1 struct]

S.data.variable.turbulence

ans = 100×100

0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 -0.0000 -0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 -0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0627 0.0640 0.0676 0.0727 0.0787 0.0850 0.0910 0.0967 0.1018 0.1062 0.1099 0.1129 0.1150 0.1164 0.1171 0.1169 0.1161 0.1145 0.1122 0.1093 0.1057 0.1014 0.0966 0.0911 0.0851 0.0785 0.0714 0.0638 0.0557 0.0471 0.0059 0.0065 0.0080 0.0099 0.0119 0.0138 0.0155 0.0169 0.0182 0.0191 0.0198 0.0203 0.0206 0.0207 0.0207 0.0206 0.0204 0.0201 0.0198 0.0195 0.0192 0.0189 0.0186 0.0183 0.0180 0.0178 0.0175 0.0173 0.0170 0.0168 0.0021 0.0044 0.0077 0.0107 0.0135 0.0159 0.0179 0.0196 0.0209 0.0218 0.0223 0.0225 0.0224 0.0221 0.0215 0.0207 0.0198 0.0188 0.0177 0.0166 0.0154 0.0142 0.0131 0.0119 0.0109 0.0099 0.0090 0.0081 0.0074 0.0068 0.0032 0.0056 0.0093 0.0128 0.0161 0.0190 0.0216 0.0237 0.0255 0.0270 0.0281 0.0288 0.0293 0.0294 0.0294 0.0291 0.0287 0.0282 0.0275 0.0267 0.0259 0.0250 0.0241 0.0231 0.0221 0.0210 0.0200 0.0189 0.0178 0.0166 0.0036 0.0060 0.0099 0.0136 0.0171 0.0202 0.0230 0.0254 0.0274 0.0291 0.0304 0.0314 0.0321 0.0325 0.0327 0.0328 0.0326 0.0324 0.0320 0.0316 0.0310 0.0305 0.0299 0.0293 0.0286 0.0279 0.0273 0.0266 0.0259 0.0252 0.0039 0.0063 0.0103 0.0142 0.0178 0.0211 0.0240 0.0265 0.0287 0.0305 0.0320 0.0332 0.0340 0.0346 0.0350 0.0352 0.0352 0.0351 0.0349 0.0347 0.0343 0.0339 0.0335 0.0331 0.0326 0.0321 0.0316 0.0312 0.0307 0.0302 0.0042 0.0066 0.0107 0.0147 0.0184 0.0219 0.0250 0.0277 0.0300 0.0320 0.0336 0.0349 0.0359 0.0367 0.0373 0.0376 0.0378 0.0379 0.0379 0.0378 0.0376 0.0374 0.0372 0.0369 0.0366 0.0363 0.0360 0.0357 0.0354 0.0350

[Rahul]

Thanks Stephen23

[Rahul]

Hi,

I again have one error which shows

Index in position 1 exceeds array bounds. Index must not exceed 1.

Would help if someone please advise the correction for error I made in the code.

sigma_diff=0.5;
beta=0.01;
gamma_nonlin=2*beta;
i=100;
j=1;
t=linspace(0,10,100);
speed_F=zeros(i,j);
source=load('D:\Rahul\Data_tokamak\data&plot\data1_non-ctrw\L-mode data from L-mode eqn\data without edge source\Fisher model\data7_L0_sig5.0_f1.mat');
mu_lmode=source.data.variable.a5_term(100,:);
turb=source.data.variable.turbulence(100,:);
for j=1:100
    speed_F=real(sqrt(sigma_diff*turb(i,j).^(1-beta).*mu_lmode(i,j)/(2*gamma_nonlin)));
end

with regards,

rc