Re: [racket-dev] Plot Contour Intervals Question (Bug?)
On 08/03/2012 11:59 AM, Doug Williams wrote: Here is a simple contour-interval example that I don't understand. [We are changing out some uses of shade in older code when I came across something I simplified to this.] Consider the following simple program. (require plot) (plot (contour-intervals (lambda (x y) (define z (- x y)) (cond (( z -1) -1) (( z 1) 1) (else z))) -2 2 -2 2)) Whose output is attached. Why is the lower white triangle not colored red - they definitely have a value of 1? It's like those points are completely ignored. It's definitely an error. Thanks for reporting it and providing a small test case. I'll fix it today and get it into the release, so if you're planning to upgrade, you can proceed as if it works. Neil ⊥ _ Racket Developers list: http://lists.racket-lang.org/dev
Re: [racket-dev] Plot Contour Intervals Question (Bug?)
On 08/03/2012 11:59 AM, Doug Williams wrote: (require plot) (plot (contour-intervals (lambda (x y) (define z (- x y)) (cond (( z -1) -1) (( z 1) 1) (else z))) -2 2 -2 2)) ... Why is the lower white triangle not colored red - they definitely have a value of 1? It's like those points are completely ignored. Turns out it was an error in the marching squares (intervals) implementation: a `' should have been a `=' to make an upper test symmetric with the corresponding lower test. I've pushed the fix. Thanks again! Neil ⊥ _ Racket Developers list: http://lists.racket-lang.org/dev
Re: [racket-dev] Plot Contour Intervals Question (Bug?)
Thanks, Neil. On Saturday, August 4, 2012 x-apple-data-detectors://32, Neil Toronto wrote: On 08/03/2012 11:59 AM, Doug Williams wrote: (require plot) (plot (contour-intervals (lambda (x y) (define z (- x y)) (cond (( z -1) -1) (( z 1) 1) (else z))) -2 2 -2 2)) ... Why is the lower white triangle not colored red - they definitely have a value of 1? It's like those points are completely ignored. Turns out it was an error in the marching squares (intervals) implementation: a `' should have been a `=' to make an upper test symmetric with the corresponding lower test. I've pushed the fix. Thanks again! Neil ⊥ _ Racket Developers list: http://lists.racket-lang.org/**dev http://lists.racket-lang.org/dev _ Racket Developers list: http://lists.racket-lang.org/dev
