poster
2019-12-10, 20:41
这个问题与我如何在MATLAB中合并这些数据有关？ (https://stackoverflow.com/questions/3071558/matlab-how-to-merge-data)
如何在IF语句中使用FIND函数？例如，如果我有此数据：
20 10 1 20 11 1 20 15 1 23 10 1 23 10 1 23 12 0 规则1：第3列的数据必须为1。
规则2：如果n是第1列的当前索引，则如果n等于n-1列的n-1 （20 = 20），则将索引n和n-1的第2列的数据合并。
20 21 0 20 15 0 20 0 0 23 20 0 23 0 0 23 12 0 编辑：
fid=fopen('data.txt'); A=textscan(fid,'%f%f%f'); fclose(fid); in = cell2mat(A)'; %'# fix for SO formatting - Jonas %# rows2mergeFrom are the rows where the second row equals the first row of col 1 %# and where the third column is 1. rows2mergeInto indicates the rows from which the %# values of the following rows should be added rows2mergeFrom = find(in(2:end,1) == in(1:end-1,1) & in(2:end,3) == 1) + 1; out = in; out(rows2mergeFrom-1,2) = out(rows2mergeFrom-1,2) + out(rows2mergeFrom,2); %# data that has been shifted up gets subtracted from the 'rows2mergeFrom'-rows out(rows2mergeFrom,2) = out(rows2mergeFrom,2) - in(rows2mergeFrom,2); %# remove the ones in the third column from any row that has been involved in a %# merge operation out([rows2mergeFrom;rows2mergeFrom-1],3) = 0 fid = fopen('newData.txt','wt'); format short g; fprintf(fid,'%g\t %g\t %g\n',out); %'# Write the data to the file fclose(fid);
回答：
无需if语句。您需要一个逻辑数组，该数组允许find提取要合并的行的行索引。
更新以符合新规则
in = [20 10 1 20 11 1 20 15 1 23 10 1 23 10 1 23 12 0]; %# rows2mergeFrom are the rows where the second row equals the first row of col 1 %# and where the third column is 1. rows2mergeInto indicates the rows from which the %# values of the following rows should be added rows2mergeFrom = find(in(2:end,1) == in(1:end-1,1) & in(2:end,3) == 1) + 1; out = in; out(rows2mergeFrom-1,2) = out(rows2mergeFrom-1,2) + out(rows2mergeFrom,2); %# data that has been shifted up gets subtracted from the 'rows2mergeFrom'-rows out(rows2mergeFrom,2) = out(rows2mergeFrom,2) - in(rows2mergeFrom,2); %# remove the ones in the third column from any row that has been involved in a %# merge operation out([rows2mergeFrom;rows2mergeFrom-1],3) = 0 out = 20 21 0 20 15 0 20 0 0 23 20 0 23 0 0 23 12 0
更多&回答... (https://stackoverflow.com/questions/3080120)
如何在IF语句中使用FIND函数？例如，如果我有此数据：
20 10 1 20 11 1 20 15 1 23 10 1 23 10 1 23 12 0 规则1：第3列的数据必须为1。
规则2：如果n是第1列的当前索引，则如果n等于n-1列的n-1 （20 = 20），则将索引n和n-1的第2列的数据合并。
20 21 0 20 15 0 20 0 0 23 20 0 23 0 0 23 12 0 编辑：
fid=fopen('data.txt'); A=textscan(fid,'%f%f%f'); fclose(fid); in = cell2mat(A)'; %'# fix for SO formatting - Jonas %# rows2mergeFrom are the rows where the second row equals the first row of col 1 %# and where the third column is 1. rows2mergeInto indicates the rows from which the %# values of the following rows should be added rows2mergeFrom = find(in(2:end,1) == in(1:end-1,1) & in(2:end,3) == 1) + 1; out = in; out(rows2mergeFrom-1,2) = out(rows2mergeFrom-1,2) + out(rows2mergeFrom,2); %# data that has been shifted up gets subtracted from the 'rows2mergeFrom'-rows out(rows2mergeFrom,2) = out(rows2mergeFrom,2) - in(rows2mergeFrom,2); %# remove the ones in the third column from any row that has been involved in a %# merge operation out([rows2mergeFrom;rows2mergeFrom-1],3) = 0 fid = fopen('newData.txt','wt'); format short g; fprintf(fid,'%g\t %g\t %g\n',out); %'# Write the data to the file fclose(fid);
回答：
无需if语句。您需要一个逻辑数组，该数组允许find提取要合并的行的行索引。
更新以符合新规则
in = [20 10 1 20 11 1 20 15 1 23 10 1 23 10 1 23 12 0]; %# rows2mergeFrom are the rows where the second row equals the first row of col 1 %# and where the third column is 1. rows2mergeInto indicates the rows from which the %# values of the following rows should be added rows2mergeFrom = find(in(2:end,1) == in(1:end-1,1) & in(2:end,3) == 1) + 1; out = in; out(rows2mergeFrom-1,2) = out(rows2mergeFrom-1,2) + out(rows2mergeFrom,2); %# data that has been shifted up gets subtracted from the 'rows2mergeFrom'-rows out(rows2mergeFrom,2) = out(rows2mergeFrom,2) - in(rows2mergeFrom,2); %# remove the ones in the third column from any row that has been involved in a %# merge operation out([rows2mergeFrom;rows2mergeFrom-1],3) = 0 out = 20 21 0 20 15 0 20 0 0 23 20 0 23 0 0 23 12 0
更多&回答... (https://stackoverflow.com/questions/3080120)