HP 50G Basic linear algebra: Matrices

1. How do I create a matrix easily?
   
   The matrix writer is the easiest method to not only create, but also view and edit
   a matrix in the HP50G.
   
   You can access it via the LSH MTRW buttons.
   After entering the elements of the matrix completely, press the ENTER key
   then store it into a variable to avoid reentering the values.
   
   Special commands such as deleting a row or a column may be learned from
   the HP 48G User's guide, Chapter 14.
   
   
2. I want to create a matrix directly. How do I enter the elements of the matrix?
   
   Press LSH [] LSH [] to mark the delimiters of the matrix.
   Enter the elements of the first row, using SPC to separate them. (no need to type a comma in RPN mode)
   Press RIGHT button to to move the cursor after the ] row delimiter.
   Press LSH [] to start a new row. When done, press ENTER.
   
   
3. How do I create an identity matrix?
   
   The identity matrix of size (n x n) may be created by the function idn(n).
   
   
4. How do I create a constant matrix?
   
   The constant matrix of size(m x n) with all values c may be created by the function
   con({m,n}, c).
   
   
5. How do I create a matrix with specified elements along the diagonal?
   
   Use the diag->({m,n),[d1, ..., dn] function. It requires the dimension of the matrix and a vector or the diagonal elements.
   
   
   
   Q. Define a zero matrix of size 4,4
   
   
6. How do I define a square matrix of random integers?
   
   Use the randm(n) function which will return an (n x n) matrix.
   
   
7. How do I transpose a matrix?
   Use the trn(M) function. This will also return the conjugate transpose for complex matrices.
   
   
8. How to I invert a matrix M.
   
   There is more than one way to do it: 1/M, M^-1, inv(M)
   
   
9. How do I define a Vandermonde matrix?
   The command for creating a square Vandermonde matrix is to specify the vector X. The output
   is the matrix consisting of columns of 1, ang the columns of powers of X. Thus vandermonde([3,4,5]) will output
   
   $$\begin{array}{lll} 1 &3 &9 \\1 &4 &16 \\1 &5 &25 \\ \end{array}$$
   
   
10. How do I multiply each element of a matrix M by a constant k?
    Simply type k * M.
    
    
    
11. How do I add or subtract a constant from all elements of a matrix M?
    There seeems to be no direct way. Create a constant matrix of the same size and
    perform the corresponding addition or subtraction.
    
    
12. How do I swap rows or columns of a matrix M?
    Consult the manual for the commands RSWAP and CSWAP functions.