Trying to use cl.interp function. It throws an IndexError depending on the length of the new color list. Steps to reproduce:

>>> colors = ['rgb(27,158,119)',
 'rgb(217,95,2)',
 'rgb(117,112,179)',
 'rgb(231,41,138)',
 'rgb(102,166,30)',
 'rgb(230,171,2)',
 'rgb(166,118,29)']
>>> works = cl.interp(colors, 10)
>>> fails = cl.interp(colors, 11)
/usr/local/lib/python2.7/dist-packages/colorlover/__init__.pyc in interp(scl, r)
   1821         c_i = int(i*math.floor(SCL_FI)/round(r[-1])) # start color index
   1822         hsl_o = rgb_to_hsl( scl[c_i] ) # convert rgb to hls
-> 1823         hsl_f = rgb_to_hsl( scl[c_i+1] )
   1824         section_min = c_i*r[-1]/SCL_FI
   1825         section_max = (c_i+1)*(r[-1]/SCL_FI)

IndexError: list index out of range

The problem is that c_i can round to len(scl)-1 depending on the length of r, hence scl[c_i+1] will end up being out of bounds. A naive solution would imply checking for that specific corner case (I'm sure there's a more elegant way though).

cl.interp(cl.scales['9']['seq']['Reds'], 100) #Works
cl.interp(cl.scales['9']['seq']['Reds'], 101) #Exception
cl.interp(cl.scales['9']['seq']['Reds'], 110) #Works

I don't see why this should happen.

See https://github.com/plotly/plotly.py/issues/1212

Though it is technically valid (https://www.w3.org/wiki/CSS3/Color/HSL), it would be helpful if colorlover didn't produce HSL color values with negative angles (e.g. 'hsl(-5, 37%, 73%)'), but instead wrapped these angles into the interval [0, 360] (e.g. 'hsl(355, 37%, 73%)' in the case above). These negative HSL values are not supported by the tinycolor2 library that Plotly.js relies on for color handling. See https://github.com/plotly/plotly.py/issues/1212#issuecomment-426981965 for more details.

Here's an example that produces negative hsl angle values

import colorlover as cl
markercl = cl.scales['11']['qual']['Paired']
cl.interp(markercl, 16)

['hsl(76.0, 52.0%, 77.0%)',
 'hsl(157.33333333333334, 64.0%, 53.0%)',
 'hsl(162.33333333333331, 65.66666666666666%, 50.66666666666667%)',
 'hsl(90.99999999999996, 56.99999999999999%, 70.00000000000001%)',
 'hsl(107.66666666666669, 56.333333333333336%, 49.999999999999986%)',
 'hsl(124.33333333333334, 55.666666666666664%, 29.999999999999986%)',
 'hsl(-7.105427357601002e-14, 92.00000000000003%, 79.00000000000003%)',
 'hsl(-77.33333333333343, 116.00000000000003%, 105.00000000000003%)',
 'hsl(478.66666666666674, 74.66666666666666%, 38.99999999999999%)',
 'hsl(718.0, 66.0%, 19.0%)',
 'hsl(-184.3333333333336, 109.00000000000001%, 85.66666666666669%)',
 'hsl(-401.6666666666673, 121.00000000000003%, 100.33333333333337%)',
 'hsl(24.999999999999996, 103.0%, 28.99999999999998%)',
 'hsl(22.333333333333336, 105.0%, 15.0%)',
 'hsl(-59.66666666666674, -63.33333333333346%, 110.66666666666671%)',
 'hsl(-85.00000000000006, -110.00000000000009%, 128.00000000000003%)']

When trying to interpolate a 9-color divergent ramp to 32 bins, I noticed a 'list index out of range' error being thrown on line 1823 of init.py. Intrigued, I ran a loop to see which bin counts worked and which didn't. Those results are posted in the space below.

If this is an expected behavior, a better error message should be thrown. If this is a bug, it will need to be investigated.

Error message:

yc in interp(scl, r)
    1821         c_i = int(i*math.floor(SCL_FI)/round(r[-1])) # start color index
    1822         hsl_o = rgb_to_hsl( scl[c_i] ) # convert rgb to hls
 -> 1823         hsl_f = rgb_to_hsl( scl[c_i+1] )
    1824         section_min = c_i*r[-1]/SCL_FI
    1825         section_max = (c_i+1)*(r[-1]/SCL_FI)

Test code:

for i in xrange(1, 1000):
    try:
        scale = cl.interp(cl.scales["9"]["div"]["RdBu"], i)
    except:
        print "{0}. Failed".format(i)
    else:
        print "{0}. Passed".format(i)

1. Failed
2. Failed
3. Failed
4. Failed
5. Failed
6. Passed
7. Passed
8. Passed
9. Passed
10. Passed
11. Failed
12. Failed
13. Failed
14. Failed
15. Failed
16. Passed
17. Passed
18. Passed
19. Passed
20. Passed
21. Failed
22. Failed
23. Failed
24. Failed
25. Failed
26. Passed
27. Passed
28. Passed
29. Passed
30. Passed
31. Failed
32. Failed
33. Failed
34. Failed
35. Failed
36. Passed
37. Passed
38. Passed
39. Passed
40. Passed
41. Failed
42. Failed
43. Failed
44. Failed
45. Failed
46. Passed
47. Passed
48. Passed
49. Passed
50. Passed
51. Failed
52. Failed
53. Failed
54. Failed
55. Failed
56. Passed
57. Passed
58. Passed
59. Passed
60. Passed
61. Failed
62. Failed
63. Failed
64. Failed
65. Failed
66. Passed
67. Passed
68. Passed
69. Passed
70. Passed
71. Failed
72. Failed
73. Failed
74. Failed
75. Failed
76. Passed
77. Passed
78. Passed
79. Passed
80. Passed
81. Failed
82. Failed
83. Failed
84. Failed
85. Failed
86. Passed
87. Passed
88. Passed
89. Passed
90. Passed
91. Failed
92. Failed
93. Failed
94. Failed
95. Failed
96. Passed
97. Passed
98. Passed
99. Passed
100. Passed
101. Failed
102. Failed
103. Failed
104. Failed
105. Failed
106. Passed
107. Passed
108. Passed
109. Passed
110. Passed
111. Failed
112. Failed
113. Failed
114. Failed
115. Failed
116. Passed
117. Passed
118. Passed
119. Passed
120. Passed
121. Failed
122. Failed
123. Failed
124. Failed
125. Failed
126. Passed
127. Passed
128. Passed
129. Passed
130. Passed
131. Failed
132. Failed
133. Failed
134. Failed
135. Failed
136. Passed
137. Passed
138. Passed
139. Passed
140. Passed
141. Failed
142. Failed
143. Failed
144. Failed
145. Failed
146. Passed
147. Passed
148. Passed
149. Passed
150. Passed
151. Failed
152. Failed
153. Failed
154. Failed
155. Failed
156. Passed
157. Passed
158. Passed
159. Passed
160. Passed
161. Failed
162. Failed
163. Failed
164. Failed
165. Failed
166. Passed
167. Passed
168. Passed
169. Passed
170. Passed
171. Failed
172. Failed
173. Failed
174. Failed
175. Failed
176. Passed
177. Passed
178. Passed
179. Passed
180. Passed
181. Failed
182. Failed
183. Failed
184. Failed
185. Failed
186. Passed
187. Passed
188. Passed
189. Passed
190. Passed
191. Failed
192. Failed
193. Failed
194. Failed
195. Failed
196. Passed
197. Passed
198. Passed
199. Passed
200. Passed
201. Failed
202. Failed
203. Failed
204. Failed
205. Failed
206. Passed
207. Passed
208. Passed
209. Passed
210. Passed
211. Failed
212. Failed
213. Failed
214. Failed
215. Failed
216. Passed
217. Passed
218. Passed
219. Passed
220. Passed
221. Failed
222. Failed
223. Failed
224. Failed
225. Failed
226. Passed
227. Passed
228. Passed
229. Passed
230. Passed
231. Failed
232. Failed
233. Failed
234. Failed
235. Failed
236. Passed
237. Passed
238. Passed
239. Passed
240. Passed
241. Failed
242. Failed
243. Failed
244. Failed
245. Failed
246. Passed
247. Passed
248. Passed
249. Passed
250. Passed
251. Failed
252. Failed
253. Failed
254. Failed
255. Failed
256. Passed
257. Passed
258. Passed
259. Passed
260. Passed
261. Failed
262. Failed
263. Failed
264. Failed
265. Failed
266. Passed
267. Passed
268. Passed
269. Passed
270. Passed
271. Failed
272. Failed
273. Failed
274. Failed
275. Failed
276. Passed
277. Passed
278. Passed
279. Passed
280. Passed
281. Failed
282. Failed
283. Failed
284. Failed
285. Failed
286. Passed
287. Passed
288. Passed
289. Passed
290. Passed
291. Failed
292. Failed
293. Failed
294. Failed
295. Failed
296. Passed
297. Passed
298. Passed
299. Passed
300. Passed
301. Failed
302. Failed
303. Failed
304. Failed
305. Failed
306. Passed
307. Passed
308. Passed
309. Passed
310. Passed
311. Failed
312. Failed
313. Failed
314. Failed
315. Failed
316. Passed
317. Passed
318. Passed
319. Passed
320. Passed
321. Failed
322. Failed
323. Failed
324. Failed
325. Failed
326. Passed
327. Passed
328. Passed
329. Passed
330. Passed
331. Failed
332. Failed
333. Failed
334. Failed
335. Failed
336. Passed
337. Passed
338. Passed
339. Passed
340. Passed
341. Failed
342. Failed
343. Failed
344. Failed
345. Failed
346. Passed
347. Passed
348. Passed
349. Passed
350. Passed
351. Failed
352. Failed
353. Failed
354. Failed
355. Failed
356. Passed
357. Passed
358. Passed
359. Passed
360. Passed
361. Failed
362. Failed
363. Failed
364. Failed
365. Failed
366. Passed
367. Passed
368. Passed
369. Passed
370. Passed
371. Failed
372. Failed
373. Failed
374. Failed
375. Failed
376. Passed
377. Passed
378. Passed
379. Passed
380. Passed
381. Failed
382. Failed
383. Failed
384. Failed
385. Failed
386. Passed
387. Passed
388. Passed
389. Passed
390. Passed
391. Failed
392. Failed
393. Failed
394. Failed
395. Failed
396. Passed
397. Passed
398. Passed
399. Passed
400. Passed
401. Failed
402. Failed
403. Failed
404. Failed
405. Failed
406. Passed
407. Passed
408. Passed
409. Passed
410. Passed
411. Failed
412. Failed
413. Failed
414. Failed
415. Failed
416. Passed
417. Passed
418. Passed
419. Passed
420. Passed
421. Failed
422. Failed
423. Failed
424. Failed
425. Failed
426. Passed
427. Passed
428. Passed
429. Passed
430. Passed
431. Failed
432. Failed
433. Failed
434. Failed
435. Failed
436. Passed
437. Passed
438. Passed
439. Passed
440. Passed
441. Failed
442. Failed
443. Failed
444. Failed
445. Failed
446. Passed
447. Passed
448. Passed
449. Passed
450. Passed
451. Failed
452. Failed
453. Failed
454. Failed
455. Failed
456. Passed
457. Passed
458. Passed
459. Passed
460. Passed
461. Failed
462. Failed
463. Failed
464. Failed
465. Failed
466. Passed
467. Passed
468. Passed
469. Passed
470. Passed
471. Failed
472. Failed
473. Failed
474. Failed
475. Failed
476. Passed
477. Passed
478. Passed
479. Passed
480. Passed
481. Failed
482. Failed
483. Failed
484. Failed
485. Failed
486. Passed
487. Passed
488. Passed
489. Passed
490. Passed
491. Failed
492. Failed
493. Failed
494. Failed
495. Failed
496. Passed
497. Passed
498. Passed
499. Passed
500. Passed
501. Failed
502. Failed
503. Failed
504. Failed
505. Failed
506. Passed
507. Passed
508. Passed
509. Passed
510. Passed
511. Failed
512. Failed
513. Failed
514. Failed
515. Failed
516. Passed
517. Passed
518. Passed
519. Passed
520. Passed
521. Failed
522. Failed
523. Failed
524. Failed
525. Failed
526. Passed
527. Passed
528. Passed
529. Passed
530. Passed
531. Failed
532. Failed
533. Failed
534. Failed
535. Failed
536. Passed
537. Passed
538. Passed
539. Passed
540. Passed
541. Failed
542. Failed
543. Failed
544. Failed
545. Failed
546. Passed
547. Passed
548. Passed
549. Passed
550. Passed
551. Failed
552. Failed
553. Failed
554. Failed
555. Failed
556. Passed
557. Passed
558. Passed
559. Passed
560. Passed
561. Failed
562. Failed
563. Failed
564. Failed
565. Failed
566. Passed
567. Passed
568. Passed
569. Passed
570. Passed
571. Failed
572. Failed
573. Failed
574. Failed
575. Failed
576. Passed
577. Passed
578. Passed
579. Passed
580. Passed
581. Failed
582. Failed
583. Failed
584. Failed
585. Failed
586. Passed
587. Passed
588. Passed
589. Passed
590. Passed
591. Failed
592. Failed
593. Failed
594. Failed
595. Failed
596. Passed
597. Passed
598. Passed
599. Passed
600. Passed
601. Failed
602. Failed
603. Failed
604. Failed
605. Failed
606. Passed
607. Passed
608. Passed
609. Passed
610. Passed
611. Failed
612. Failed
613. Failed
614. Failed
615. Failed
616. Passed
617. Passed
618. Passed
619. Passed
620. Passed
621. Failed
622. Failed
623. Failed
624. Failed
625. Failed
626. Passed
627. Passed
628. Passed
629. Passed
630. Passed
631. Failed
632. Failed
633. Failed
634. Failed
635. Failed
636. Passed
637. Passed
638. Passed
639. Passed
640. Passed
641. Failed
642. Failed
643. Failed
644. Failed
645. Failed
646. Passed
647. Passed
648. Passed
649. Passed
650. Passed
651. Failed
652. Failed
653. Failed
654. Failed
655. Failed
656. Passed
657. Passed
658. Passed
659. Passed
660. Passed
661. Failed
662. Failed
663. Failed
664. Failed
665. Failed
666. Passed
667. Passed
668. Passed
669. Passed
670. Passed
671. Failed
672. Failed
673. Failed
674. Failed
675. Failed
676. Passed
677. Passed
678. Passed
679. Passed
680. Passed
681. Failed
682. Failed
683. Failed
684. Failed
685. Failed
686. Passed
687. Passed
688. Passed
689. Passed
690. Passed
691. Failed
692. Failed
693. Failed
694. Failed
695. Failed
696. Passed
697. Passed
698. Passed
699. Passed
700. Passed
701. Failed
702. Failed
703. Failed
704. Failed
705. Failed
706. Passed
707. Passed
708. Passed
709. Passed
710. Passed
711. Failed
712. Failed
713. Failed
714. Failed
715. Failed
716. Passed
717. Passed
718. Passed
719. Passed
720. Passed
721. Failed
722. Failed
723. Failed
724. Failed
725. Failed
726. Passed
727. Passed
728. Passed
729. Passed
730. Passed
731. Failed
732. Failed
733. Failed
734. Failed
735. Failed
736. Passed
737. Passed
738. Passed
739. Passed
740. Passed
741. Failed
742. Failed
743. Failed
744. Failed
745. Failed
746. Passed
747. Passed
748. Passed
749. Passed
750. Passed
751. Failed
752. Failed
753. Failed
754. Failed
755. Failed
756. Passed
757. Passed
758. Passed
759. Passed
760. Passed
761. Failed
762. Failed
763. Failed
764. Failed
765. Failed
766. Passed
767. Passed
768. Passed
769. Passed
770. Passed
771. Failed
772. Failed
773. Failed
774. Failed
775. Failed
776. Passed
777. Passed
778. Passed
779. Passed
780. Passed
781. Failed
782. Failed
783. Failed
784. Failed
785. Failed
786. Passed
787. Passed
788. Passed
789. Passed
790. Passed
791. Failed
792. Failed
793. Failed
794. Failed
795. Failed
796. Passed
797. Passed
798. Passed
799. Passed
800. Passed
801. Failed
802. Failed
803. Failed
804. Failed
805. Failed
806. Passed
807. Passed
808. Passed
809. Passed
810. Passed
811. Failed
812. Failed
813. Failed
814. Failed
815. Failed
816. Passed
817. Passed
818. Passed
819. Passed
820. Passed
821. Failed
822. Failed
823. Failed
824. Failed
825. Failed
826. Passed
827. Passed
828. Passed
829. Passed
830. Passed
831. Failed
832. Failed
833. Failed
834. Failed
835. Failed
836. Passed
837. Passed
838. Passed
839. Passed
840. Passed
841. Failed
842. Failed
843. Failed
844. Failed
845. Failed
846. Passed
847. Passed
848. Passed
849. Passed
850. Passed
851. Failed
852. Failed
853. Failed
854. Failed
855. Failed
856. Passed
857. Passed
858. Passed
859. Passed
860. Passed
861. Failed
862. Failed
863. Failed
864. Failed
865. Failed
866. Passed
867. Passed
868. Passed
869. Passed
870. Passed
871. Failed
872. Failed
873. Failed
874. Failed
875. Failed
876. Passed
877. Passed
878. Passed
879. Passed
880. Passed
881. Failed
882. Failed
883. Failed
884. Failed
885. Failed
886. Passed
887. Passed
888. Passed
889. Passed
890. Passed
891. Failed
892. Failed
893. Failed
894. Failed
895. Failed
896. Passed
897. Passed
898. Passed
899. Passed
900. Passed
901. Failed
902. Failed
903. Failed
904. Failed
905. Failed
906. Passed
907. Passed
908. Passed
909. Passed
910. Passed
911. Failed
912. Failed
913. Failed
914. Failed
915. Failed
916. Passed
917. Passed
918. Passed
919. Passed
920. Passed
921. Failed
922. Failed
923. Failed
924. Failed
925. Failed
926. Passed
927. Passed
928. Passed
929. Passed
930. Passed
931. Failed
932. Failed
933. Failed
934. Failed
935. Failed
936. Passed
937. Passed
938. Passed
939. Passed
940. Passed
941. Failed
942. Failed
943. Failed
944. Failed
945. Failed
946. Passed
947. Passed
948. Passed
949. Passed
950. Passed
951. Failed
952. Failed
953. Failed
954. Failed
955. Failed
956. Passed
957. Passed
958. Passed
959. Passed
960. Passed
961. Failed
962. Failed
963. Failed
964. Failed
965. Failed
966. Passed
967. Passed
968. Passed
969. Passed
970. Passed
971. Failed
972. Failed
973. Failed
974. Failed
975. Failed
976. Passed
977. Passed
978. Passed
979. Passed
980. Passed
981. Failed
982. Failed
983. Failed
984. Failed
985. Failed
986. Passed
987. Passed
988. Passed
989. Passed
990. Passed
991. Failed
992. Failed
993. Failed
994. Failed
995. Failed
996. Passed
997. Passed
998. Passed
999. Passed

The following code

import colorlover as cl
cl.interp( cl.scales['3']['div']['RdYlBu'], 5) 

generates:

---------------------------------------------------------------------------
ZeroDivisionError                         Traceback (most recent call last)
<ipython-input-8-14a39fa30bf3> in <module>()
      1 import colorlover as cl
----> 2 cl.interp( cl.scales['3']['div']['RdYlBu'], 5)

/Users/garyfeng/anaconda/lib/python2.7/site-packages/colorlover/__init__.py in interp(scl, r)
   1821         # garyfeng: c_i could be rounded up so scl[c_i+1] will go off range
   1822         #c_i = int(i*math.floor(SCL_FI)/round(r[-1])) # start color index
-> 1823         c_i = int(math.floor(i*math.floor(SCL_FI)/round(r[-1]))) # start color index
   1824         hsl_o = rgb_to_hsl( scl[c_i] ) # convert rgb to hls
   1825         hsl_f = rgb_to_hsl( scl[c_i+1] ) if c_i < len(scl)-1 else hsl_o

ZeroDivisionError: float division by zero

Apparently round(r[-1])==0.

Classifiers are metadata about packages on PyPI. The information about Python version support shows on the PyPI project page and are used by tools such as caniusepython3.

I noticed that the colorlover package has no license file or license declaration in setup.py. Is it intended to be under MIT like plot.ly? If so, could you clarify that by adding a license file.

I'm playing around with interp, and it seems to give some weird intermediate values. For example, in the docs for colorlover there is a section of the 'BuPu' colormap that cycles through hues early on:

I've found similar things when doing this with my own colormaps, e.g.:

This doesn't seem to be as big of a problem w/ fewer bins:

Any idea what's going on?

I don't see a license in the repo. How would you feel about contributing the color dictionary to Plots.jl so that these gradients could be used for all backends (including Plotly)?

Fixes #18 by interpolating the Hue component of HSL colors as angles (rather that a pure linear interpolation). For example, the angle half way between 10 deg and 350 deg should be 0 not 180.

Also fixed an error in the calculation of the Hue component in rgb_to_hsl (971ef35)

Results:

Various maintenance fixes:

• Migrate to circleci 2.0
• distutils -> setuptools
• Add conda recipe
• Add MANIFEST.in to include README/LICESNE in PyPI packages.

Dear developers of colorlover tool, I was trying to reverse the colors of "Spectral" in the Diverging category. I thought the function cl.flipper( scale=None ) could achieve this. However, it didn't. From your GitHub webpage, the results of cl.flipper()['div']['3']['RdYlBu'] and cl.scales['3']['div']['RdYlBu'] are the same, the same sequence of the three returned rgb combinations. This perhaps explains why I didn't see reverse Spectral. I tried cl.scales['3']['div']['Spectral_r'], i.e., by adding _r, and it didn't work either. I am not sure if this is a problem or not. Could you please teach me how to reverse the color scale of your tool? Thank you in advance for your insights.

Perhaps more of an issue with plotly's website but the README points to this page (https://plot.ly/ipython-notebooks/color-scales/) which used to be a notebook of helpful lists of all of the palettes in colorlover

However that link now redirects to here: (https://plotly.com/python/builtin-colorscales/) and none of colorlovers palettes or features are listed.

Is there a way to get access to the old notebook somehow?

Thanks!

Would be nice if this awesome library would allow creating color scales from numpy arrays. Right now it only detects numeric color scale if it strictly consists of tuples (explicit check in scale_type).

It would be useful if the license used could also be specified in setup.py, as then it can be displayed correctly by pip-licenses. This would involve a change like:

 setup(
     ...
+    license='MIT',
     ...