MATLAB: Read text file from function

Question

Hi!

Im trying an old course matlab program and it read data from a text file but it isnt working and i cant figure out whats wrong. Im not familiar with reading in files from matlab functions, hope someone can help me out? Please see attached files. Can someone see if the command below will function as it should?

fid = fopen('truss2D.inp','r');

[node,element,Dzero,Fs,elem_force,Nn,Ne] = read_input(fid);

fclose(fid);

The text files has the following text:

*NODE [Node number, X-coordinate, Y-coordinate]

1, 0.0, 0.0

2, 4.0, 3.0

3, 0.0, 3.0

*ELEMENT [Element no., Node 1, Node 2, E, A]

1, 1, 2, 200e9, 25.0e-4

2, 2, 3, 200e9, 4.0e-4

3, 1, 3, 200e9, 6.0e-4

*ZeroDiplacement [Node number, D.O.F.]

1,1

2,1

2,2

3,2

*PointForce [Node number, D.O.F., force value]

1,2, -5.0e4

*VolumeForce [Element number, q0, q1, q2]

3, -1.0e7, 0, 0

*END

% This routine reads in-put data from the file "truss2D.inp"

function [node,element,Dzero,Fs,elem_force,Nn,Ne] = read_input(fid)

data = [];

%

% Node numbers and coordinates

data = str2num(fopen(fid));

data = str2num(fopen(fid));

while (length(data) > 0)

Nnum = round(data(1));

node(Nnum,1:2) = data(2:3);

data = str2num(fopen(fid));

end

Nn = length(node(:,1));

%

% Elements (connectivity, E & A)

data = str2num(fopen(fid));

while (length(data) > 0)

Enum = round(data(1));

element( Enum, 1:4) = data(2:5);

data = str2num(fopen(fid));

end

Ne = length(element(:,1));

%

% Zero displacement Boundary Conditions

Dzero = zeros(2*Nn,1);

data = str2num(fopen(fid));

while (length(data) > 0)

if (data(2) == 1)

Dzero(2*data(1)-1) = 1;

elseif (data(2) == 2)

Dzero(2*data(1)) = 1;

end

data = str2num(fopen(fid));

end

%

% Applied point forces

Fs = zeros(2*Nn,1);

data = str2num(fopen(fid));

while (length(data) > 0)

if (data(2) == 1)

Fs(2*data(1)-1) = data(3);

elseif (data(2) == 2)

Fs(2*data(1)) = data(3);

end

data = str2num(fopen(fid));

end

%

% Applied volume forces

elem_force = zeros(Ne,4);

data = str2num(fopen(fid));

while (length(data) > 0)

elem_force(data(1),:) = data;

data = str2num(fopen(fid));

end

return

%*************************************************************

Answer 1

Hi again,

here's a script that processes the input files. There are two parameters missing n, Ne. Implement these and convert this script to function.

Note: it uses ReadFile function.

clc;
clear;
format long g % Element contains 1E11 number, other elements are not displayed nicely without this
fileData = ReadFile('truss2D_inp.txt');
keywordGroup = contains(fileData, '*'); % Returns logical array where character '*' is found
keywordStrings = {'Node', 'Element', 'ZeroDisplacement', ...
    'PointForce', 'VolumeForce'}; 
emptyVals = cell(size(keywordStrings)); 
structPairs = reshape([keywordStrings;emptyVals], 1, []); % Reshape into name-value pair for struct
inputData = struct(structPairs{:});
% Looping over fileData
jj = 0;
for ii = 1 : length(fileData)
    if keywordGroup (ii) % if '*' is found, increment the keywordStrings index
        jj = jj + 1;
    else
        inputData(ii).(keywordStrings{jj}) = str2num(fileData{ii});
    end
end
% Processed data
Node = vertcat(inputData.(keywordStrings{1}));
finElement = vertcat(inputData.(keywordStrings{2}));
fixedDisp = vertcat(inputData.(keywordStrings{3}));
pForce = vertcat(inputData.(keywordStrings{4})); 
volumeForce = vertcat(inputData.(keywordStrings{5})); 
% missing N and NE

function fileData = ReadFile(inputFilePath)
% Function reads supplied filepath and outputs it as the cell fileData
fileData = splitlines(fileread(inputFilePath));
end