As I understand, you want to store the information from every text block that that meet the constraints specified by you in different columns of the same row.
You may refer to the steps mentioned below to do so:
1. First, you can read the “exchange.txt” into memory, split it into lines, and trim the lines to discard unnecessary content. This can be done using the following code snippet:
file_content = fileread('exchange.txt');
lines = transpose(strsplit(file_content, '\n'));
lines = lines(45:end);
block_seperator = '----------------------------------------------------------------------------------------';
lines(size(lines,1)+1) = {block_seperator};
block_size = 9;
blocks = {};
num_blocks = 0;
You may refer to MathWorks Documentation for more information on “strsplit” function. Here is the link to it:
2. Next, from visual inspection of the file it can be observed that the blocks are nine lines long. You can use this to separate the lines into blocks and store them in a cell array. This can be done as follows:
line_idx = 1;
while(line_idx < size(lines,1))
num_blocks = num_blocks+1;
blocks{num_blocks} = lines(line_idx:line_idx+block_size);
line_idx = line_idx + block_size;
end
blocks = transpose(blocks);
3.You can iterate through the blocks using a for loop, extract information corresponding to the parameters “i”, “j”, “R”, “J_iso(meV)”, “vector”, “distance”,” J_iso”, “J_prim”, “DMI” and “J_ani”, and store these parameters separately it in a MATLAB struct data structure. These can then be accessed using dot indexing.
blocks_struct = {};
for block_idx = 1:size(blocks,1)
block = blocks{block_idx};
% create the block struct
block{2} = strrep(block{2}, '( ', '(');
block{2} = strrep(block{2}, '( ', '(');
block{2} = strrep(block{2}, ' )', ')');
first_line_elements = strsplit(block{2}, ' ');
block_struct.i = first_line_elements{2};
block_struct.j = first_line_elements{3};
block_struct.R = [first_line_elements{4}, first_line_elements{5}, first_line_elements{6}];
block_struct.J_iso_meV = first_line_elements{7};
block_struct.vector = [first_line_elements{8}, first_line_elements{9}, first_line_elements{10}];
block_struct.distance = first_line_elements{11};
second_line_elements = strsplit(block{3},':');
block_struct.J_iso = second_line_elements{2};
third_line_elements = strsplit(block{4},':');
block_struct.J_prime = strsplit(third_line_elements{2},',');
block_struct.J_prime = block_struct.J_prime{1};
block_struct.B = third_line_elements{3};
fourth_line_elements = strsplit(block{5},':');
block_struct.DMI = fourth_line_elements{2};
block_struct.J_ani = {block{7}(2:end),block{8},block{9}(1:end-2)};
blocks_struct{block_idx} = block_struct;
end
blocks_struct = transpose(blocks_struct);
For more information on “strrep” function, refer to the link of MathWorks documentation mentioned below:
4. Subsequently, you can iterate through the individual blocks which satisfy the constraints of “i” is “Cr2” and “j” is either “Cr3” or “Cr4”, and then store the distance, J_iso, and DMI values in a cell array. This can be accomplished using the following code snippet:
stored_info = {};
cnt = 1;
for block_idx = 1:size(blocks_struct,1)
block = blocks_struct{block_idx};
if block.i == 'Cr2'
if block.j == 'Cr3' | block.j == 'Cr4'
stored_info{cnt}={block.distance, block.J_iso, block.DMI};
disp(stored_info{cnt});
cnt = cnt + 1;
end
end
end
In this way, you can store the required information.
I hope this is helpful!
