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entering vectors and +/- sign - mcjtom - 08-09-2014 11:47 AM
I can't figure out what's the usefulness of +/- symbol when entering vectors (i.e. if [] brackets are hit, the brackets appear as [x +/-]. What does +/- do inside the brackets?
Cheers!
RE: entering vectors and +/- sign - Helge Gabert - 08-09-2014 03:08 PM
Expands and contracts rows/columns, and enables one to traverse large matrices quickly with the arrow keys. Hit - or + when you're on the symbol and you'll see.
RE: entering vectors and +/- sign - Joe Horn - 08-09-2014 04:50 PM
(08-09-2014 03:08 PM)Helge Gabert Wrote: Expands and contracts rows/columns, and enables one to traverse large matrices quickly with the arrow keys. Hit - or + when you're on the symbol and you'll see.
Less well known is the fact that pressing × (multiply) creates a new row or column BEFORE the current one (unlike + which creates it AFTER the current one). It's the only way to insert a new first row or new first column.
RE: entering vectors and +/- sign - Helge Gabert - 08-09-2014 10:30 PM
Thanks - - I learned something, too!
RE: entering vectors and +/- sign - mcjtom - 08-11-2014 10:49 AM
Thanks!
On somewhat related topic: how do I convert a row (or column matrix) to a vector (i.e. lose double square brackets?
RE: entering vectors and +/- sign - Eddie W. Shore - 08-11-2014 12:47 PM
I don't recall seeing a command to convert single-row/column matrices into vectors.
Workaround for a single row matrix:
1. Store the matrix. For example, M0.
2. Execute M0(1).
Example: Starting with [[4,2]]:
M0:= [[4,2]]
M0(1) returns [4,2]
RE: entering vectors and +/- sign - Joe Horn - 08-11-2014 04:24 PM
(08-11-2014 10:49 AM)mcjtom Wrote: On somewhat related topic: how do I convert a row (or column matrix) to a vector (i.e. lose double square brackets?
From the keyboard, just copy it to the edit line, place the cursor anywhere within the single-row matrix, and press Shift 5 (the square-bracket key). Shift 5 toggles between matrix and vector. Very handy.