how to read txt file with delimeter

Hey guys i have read particular data from text file with header shown below

Freq. V(x)

0.00000000000000e+000 (3.28243072429145e+000dB,0.00000000000000e+000°)

1.00000000000000e+000 (-6.45914961580970e+000dB,-1.65794548852105e+000°)

I want the read this data alone and negelect remaining datas

0.00000000000000e+000 3.28243072429145e+000dB

1.00000000000000e+000 -6.45914961580970e+000dB

could anyone please assist me on this?

Answer 1

[Cris LaPierre]

See this page: Import Text Files

[Venkatkumar M]

clc;
clear all;
t=readtable('se.txt');
r=(t(:,1));
s=(t(:,2)); 

using above code i am able to separate freq and vo to 1hz and (3.28243072429145e+000dB,0.00000000000000e+000°) respectively

how to delimeter comma , and braces ()

could you please on it?

[Cris LaPierre]

Share your file. You can attach it to your post using the paperclip icon.

[Venkatkumar M]

here is the file attached

[Cris LaPierre]

This one is a little more challenging because of its formatting. Here's one way to do it with readtable. The data is returned in a table, so see this page on how to access the data.

c = readtable("c.txt",'Format','%f %*c %f %*s');
c.Properties.VariableNames = ["Freq","dB"]

[Venkatkumar M]

thank you so much cris

[Venkatkumar M]

@Cris LaPierre

I tried same method for attached file but i could not do it.

But also I want to be like

From

1.00000000000000e+002 (1.60224937311493e+001dB,6.76633028351092e+001°) (1.60798220522945e+001dB,8.52624997624123e+001°)

To

1.00000000000000e+002 1.60224937311493e+001dB 6.76633028351092e+001° 1.60798220522945e+001dB 8.52624997624123e+001°

Each value in separate column.

Could you please help me?

[Cris LaPierre]

Did you take into consideration that this data set has 3 columns? Please share the code you have tried.

The only way to include the units is to read in the number and unit as a string. I find storing numbers as strings to not be very useful.

[Cris LaPierre]

EDIT: The post I responded to was removed. Here is a screenshot

I discovered a simpler way. Try this.

file = 'https://www.mathworks.com/matlabcentral/answers/uploaded_files/1196783/r4.4u_db.txt';
r4 = readmatrix(file,'Delimiter',["\t",","],'TrimNonNumeric',true)

r4 = 6178×3

20.0000 65.2532 -89.9983 20.0461 65.2332 -89.9983 20.0923 65.2132 -89.9983 20.1386 65.1932 -89.9983 20.1851 65.1732 -89.9983 20.2316 65.1532 -89.9983 20.2782 65.1332 -89.9983 20.3250 65.1132 -89.9983 20.3718 65.0932 -89.9983 20.4188 65.0732 -89.9983

For converting db to linear, consider using the db2mag function (requires the Control Systems Toolbox).

tiledlayout(2,1)
nexttile
semilogx(r4(:,1),db2mag(r4(:,2)))
grid on

nexttile
semilogx(r4(:,1),r4(:,3))
grid on