The Museum of HP Calculators

HP Forum Archive 19

 Casio Prizm screenshotMessage #1 Posted by Don Shepherd on 18 Dec 2010, 10:27 p.m. Here is a screenshot from the Casio Prizm, showing the graph of two inequalities, y>=x+1 and y<2x+3. The dark shaded area is the solution to both inequalities. The actual screen looks somewhat crisper than the screenshot.

Re: Casio Prizm screenshot
Message #2 Posted by Thomas Klemm on 19 Dec 2010, 2:33 p.m.,
in response to message #1 by Don Shepherd

What an improvement compared to what we can do with an HP-48G:

Since I'm not that familiar with plotting I had to consult the manual. You need two different plot-types: TRUTH and CONS. As suggested in the manual I created two variables:

INEQ

'Y\>=X+1 AND Y<2*X+3'


EQNS

{ 'Y=X+1' 'Y=2*X+3' }


Now you can choose one or the other for EQ. Don't ERASE the graph after drawing the first plot.

Currently I'm reading the fun of programming. There's a chapter dealing with images (7 Functional images). So I wondered whether I could do that with my HP-48 as well. Here we go:

## Checker

checker

\<<
FLOOR SWAP
FLOOR +
2 MOD
NOT
\>>


EQ

\<< Y X checker \>>


## Polar Checker

toPolar

\<<
R\->C DUP
ABS SWAP ARG
\>>


n = 10

EQ

\<<
Y X
toPolar
\pi /
n *
checker
\>>


## Swirl Vertical Strip

vstrip

\<< ABS .5 \<= \>>


fromPolar

\<<
\-> r \Gh
\<<
\Gh SIN r *
\Gh COS r *
\>>
\>>


r = 1

EQ

\<<
Y X toPolar
OVER
2 * \pi *
r / +
fromPolar
vstrip
\>>


Now this turns out to be very slow. Moreover I received an "Insufficent Memory" error and had to plot the image in several runs. Not exactly what you want.

Still I hope these examples might be inspiring.

Best regards
Thomas

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