How do I enter an imaginary number into a matrix

Loading [MathJax]/jax/output/HTML-CSS/jax.js

First time here? Check out the FAQ!

linear-algebra

Chisx
11 ●1 ●1 ●2

In a very simple example, I am created a 2 by 2 matrix like this

var('i')
ran40 = matrix(QQ,2,2,[[2*i,-2],[3,4]])
show(ran40)

I need to eventually call show(ran40.rref()) so that I can see the reduced row echelon form of the above matrix. But I get syntax errors in the creation of the matrix above.

How do I simply put the imaginary letter i into a matrix and then it actually be computed on. That is, the imaginart "part" is actually used in the RREF computation.

Comments

See also the question (and answer) at http://stackoverflow.com/questions/35...

kcrisman ( 9 years ago )

add a comment

1 Answer

Sort by » oldest newest most voted

answered 9 years ago

tmonteil
27483 ●32 ●205 ●519 http://wiki.sagemath.o...

updated 9 years ago

When you write var('i'), you define i as a symbol. In particular, 2*i is an element of the symbolic ring, not the rationals, but you ask that 2*i be an entry of a matrix whose coefficients are rationals (because of the QQ at the beginnig).

If you want the imaginary number, you should use the already defined I, if you want a matrix over, say the algabraic numbers QQbar (so that I in an element), you should write:

sage: matrix(QQbar,2,2,[[2*I,-2],[3,4]])
[2*I  -2]
[  3   4]

link

add a comment

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Question Tools

Stats

Asked: 9 years ago

Seen: 1,786 times

Last updated: Feb 25 '16

How do I enter an imaginary number into a matrix savecancel

Comments

1 Answer