我有一个带有表格的 .csv 文件，我按如下方式导入该文件:
mydata = readtable('datafile1.csv');
该表有 2549 行和 28 列。下面是表格的一部分，其中包含所有列，但有一些行，举个例子:
ID subject A B C D E F G H I J K L M N O P Q R S T U V W X Y
'sbj05100' 'sbj05' 6.22316646575928 85 -2.31806182861328 339 14 100022 'tf' 48401 100 2 2 'no' 'h' 339 322.507000000000 339 'sbj05' 100 100021 286 1 419 1.95000000000000 2 1 662
'sbj05102' 'sbj05' 7.60787820816040 65 3.00547647476196 405 17 102012 'tf' 59201 102 1 2 'yes' 'h' 405 385.367000000000 405 'sbj05' 102 102011 283 1 283 1.89000000000000 1 1 364
'sbj05104' 'sbj05' -3.71897959709167 81 3.80262303352356 429 19 104012 'tf' 66401 104 1 2 'yes' 'h' 429 408.228000000000 429 'sbj05' 104 104011 266 1 266 2.19000000000000 2 1 244
'sbj09152' 'sbj09' 0.181026369333267 88 -0.0696721449494362 87 4 152042 'tf' 12401 152 4 2 'no' 'l' 87 82.8280000000000 87 'sbj09' 152 152041 297 1 297 1.25000000000000 1 1 354
'sbj09157' 'sbj09' 0.309507131576538 116 0.226024463772774 51 2 157042 'tf' 5201 157 4 2 'no' 'l' 51 48.4870000000000 51 'sbj09' 157 157041 273 1 273 1.45000000000000 1 1 279
'sbj10151' 'sbj10' 6.99367523193359 90 4.86872243881226 345 20 151022 'tf' 70001 151 2 2 'no' 'h' 345 328.224000000000 345 'sbj10' 151 151021 198 1 198 3 1 1 310
'sbj10167' 'sbj10' 2.25431561470032 152 -0.200379326939583 129 7 167012 'tf' 23201 167 1 2 'yes' 'h' 129 122.675000000000 129 'sbj10' 167 167011 110 1 110 2.32000000000000 2 1 276
'sbj10168' 'sbj10' 3.22731518745422 147 4.72183227539062 93 3 168042 'tf' 8801 168 4 2 'no' 'l' 93 88.3230000000000 93 'sbj10' 168 168041 179 1 179 2.38000000000000 2 1 132
我需要计算每个主题(主题列)和每个条件的B列的平均值，并分别计算C列的平均值(I 列)。 我想要得到的是:
for sbj05 column B --> cond 1 = (65+81)/2
cond2 = 85
column C --> cond 1 = (3.005476475+3.802623034)/2
cond2 = -2.3180618
and so on...
我尝试点击此链接 in matlab, calculate mean in a part of one column where another column satisfies a condition .
[R, I, J] = unique(mydata(:,2));
% count the repeating entries: now we have integer indices!
counts = accumarray(J, 1, size(R));
% sum the 2nd column for all entries
sums = accumarray(J, mydata(:,4), size(R)); %for column B
% compute means
means = sums./counts;
但我收到此错误:
Undefined function 'accumarray' for input arguments of type 'table'.
有什么建议吗？
最佳答案
方便的是，Matlab 有一个计算表格统计数据的函数。因此，您可能需要使用 grpstats，而不是 accumarray:
meanPerSubjectAndCondition = grpstats(mydata,{'subject','I'},'mean','DataVars',{'B','C'})
关于matlab - 计算表中某列的某些行的平均值，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/34271169/