CODEWITHSUNDEEP
rmatrixmatrix-multiplicationtranspose
user3505808
user3505808

Reputation: 435

Matrix expression causes error "requires numeric/complex matrix/vector arguments"?

ma=diag(3)+t(da)%*%da

R Code above, error message as follows:

Error in t(da) %*% da : requires numeric/complex matrix/vector arguments

da is a matrix, looks as following:

V45       V46          V47          V48         V49         V50          V51    
1    0.461727059  2.357732985 -1.536932071 -1.34425710  0.893541975 -0.0676913075 -0.86532231
2    0.253022555  1.524473647 -0.588911138 -1.65207275 -0.072255170 -0.5212951533 -1.43686625
3    0.824678362  1.497001189  0.335973892 -0.84027799  0.275289411 -0.2921928001 -0.16277595
4    0.854530787  2.258305198  0.107346531 -1.69194014 -0.841572928 -1.1153931009 -1.939461341
5    1.148286984 -0.232390389 -0.498465734 -0.45728816  0.352889082  0.9868844505 -0.68401129

Could anyone help me to figure out the error?

Upvotes: 38

Views: 142096

Answers (5)

Miff
Miff

Reputation: 7941

To get the matrix multiplication to work, you need to convert the data.frame (presumably that's what da is) to a matrix. Calculating the transpose with t() automatically does this:

t(da)%*%as.matrix(da)

But this gives a 7x7 matrix which can't be added to the 3x3 identity matrix that you're using. Do you mean something like:

ma=diag(7)+t(da)%*%as.matrix(da)

You may like to have a look at An Introduction to R if you don't feel confident about the difference between a matrix and data.frame.

Upvotes: 61

stevec
stevec

Reputation: 52208

Since a lot of machine learning libraries use matrix multiplication, if one or more of your inputs are of class character but the algorithm expects numeric, you could experience a similar error message.

TL;DR double-check that your inputs are of class numeric. If they're not, use as.numeric() to convert character to numeric. That solved for me using the qmap package's fitQmapRQUANT() function.

Upvotes: 1

Jeff
Jeff

Reputation: 724

Just in addition, you get this error if you attempting to pass a data frame where a matrix should be.

Upvotes: 0

Anonymous
Anonymous

Reputation: 1

Matrix expression causes error “requires numeric/complex matrix/vector arguments”?

This error occurs because you are passing a String in vector and As string cannot be multiply. matrix(c('1','2','2','1'), nrow=2,ncol=2,byrow=TRUE)->> J

To correct it pass a numeric/complex arguments it works. matrix(c(1,2,2,1), nrow=2,ncol=2,byrow=TRUE)->> j

then use this t = j %*% t(j) //it will print the multiplication of matrix transpose and matrix. print(t)

Upvotes: -2

Steffen J.
Steffen J.

Reputation: 742

See also this solution: https://bugs.r-project.org/bugzilla/show_bug.cgi?id=16607

I couldn't figure out what was wrong with combat, so I tried to run PCA (function prcomp) on my dataset. R kept telling me that the input is not a matrix, even though when checking the class of the input object, it did say 'matrix' and mode 'numeric'. After restarting my IDE (Architect in my case), everything was running fine with combat and with PCA.

Upvotes: -2

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