Matlab - read textfile and extract data from specific row - matlab

Question

I have a text file which is an output from the command line of a diff program.
I now read the file using
fileID = fopen('runInfo.out','r');
file_dump = textscan(fileID, '%s', 'Delimiter', '\n');
% Find postion of Min Cp to mark field on interest
Row = find(~cellfun('isempty',strfind(file_dump{1}, 'Minimum Viscous Cp')));
fclose(fileID);
I now have the row from which I need to extract data.
The format of the file from this location looks something like
.OPERv c>
u/Uinf = 1.0050 v/Uinf = -0.0029
q/Uinf = 1.0050 Cp = -0.0100
.OPERv c>
u/Uinf = 1.0088 v/Uinf = -0.0075
q/Uinf = 1.0088 Cp = -0.0177
.OPERv c>
u/Uinf = 1.0156 v/Uinf = -0.0281
q/Uinf = 1.0160 Cp = -0.0323
Since I already have this data in my cellArray from textscan,
What I could think of was (pretty non robust)
u_line = vertcat(file_dump{1,1}...
{find(~cellfun('isempty',strfind(file_dump{1}, 'u/Uinf'))),1})
v = str2num(u_line(:,end-5:end));
and then somehow extract the numbers from these returned cells?
In the end, I need the four values of u/Uinf, v/Uinf, q/Uinf and Cp.
Is there a simpler option that I am missing?

Answer 1

If the text file from which to extract the data is the one you posted in the sedond box, you can use a AWK script.
The followng AWK script reads the text file and generates as output a MatLab .m file containing the values extracted form the text file as arrays.
AWK script
BEGIN {
u_cnt=1;
v_cnt=1;
c_cnt=1;
q_cnt=1;
}
{
if($1 == "u/Uinf")
{
u_Uinf[u_cnt]=$3
u_cnt++
}
if($4 == "v/Uinf")
{
v_Uinf[v_cnt]=$6
v_cnt++
}
if($4 == "Cp")
{
cp[c_cnt]=$6
c_cnt++
}
if($1 == "q/Uinf")
{
q_Uinf[q_cnt]=$3
q_cnt++
}
}
END {
print "u_Uinf_data=[" > "txt_file_data.m"
for(i=1;i<u_cnt;i++)
print u_Uinf[i] > "txt_file_data.m"
print "];" > "txt_file_data.m"
print "v_Uinf_data=[" > "txt_file_data.m"
for(i=1;i<v_cnt;i++)
print v_Uinf[i] > "txt_file_data.m"
print "];" > "txt_file_data.m"
print "q_Uinf_data=[" > "txt_file_data.m"
for(i=1;i<q_cnt;i++)
print q_Uinf[i] > "txt_file_data.m"
print "];" > "txt_file_data.m"
print "cp_data=[" > "txt_file_data.m"
for(i=1;i<c_cnt;i++)
print cp[i] > "txt_file_data.m"
print "];" > "txt_file_data.m"
}
Output .m file
u_Uinf_data=[
1.0050
1.0088
1.0156
];
v_Uinf_data=[
-0.0029
-0.0075
-0.0281
];
q_Uinf_data=[
1.0050
1.0088
1.0160
];
cp_data=[
-0.0100
-0.0177
-0.0323
];