Horrible!

[Piotr]

When I select a single metric distortion (not mixed one) it's not smooth! That's horrible! It wouldn't be a problem if mixed ones weren't smooth either.

[Piotr]

There should be an option for gradiations, instead of forcing them on single metric distortions and not allowing them for mixed distortions. That's stupid. Also, it glitches when I set 256 gradiations.

[daan]

Noted. Thanks.

— daan

[Piotr]

Also, on the "Change Projection..." (which I refer to as "samples"), the gradiations appear in conformal projections and equal-area projections, making only the equidistant/compromise sample Distortion Visualization... maps look good; the sample Distortion Visualization... maps of conformal and equal-area projections look horrible!

[Atarimaster]

Also, it glitches when I set 256 gradiations.

So, set it to 255 (that’s e.g. 255 shades of red plus white = 256 different colors).
I always assumed that the only bug is the error message that says "Gradations must be between 2 and 256" (instead of "between 2 and 255").

[daan]

I have several things to say about this.

1. Apologies the verbiage is unclear. English is ambiguous that way; when we say “between”, it’s not clear whether the end values are included or excluded.

2. Concerning the original complaint: It’s nonsensical to use gradations for mixed angular and areal distortion because, in mixed form, those gradations normally don’t exist. Angular deformation and areal inflation/deflation (“flation”) do not generally follow the same paths. This is why mixed distortion is continuous rather than in gradations. This is also why there is no option for it.

3. Meanwhile, using continuous tones for pure angular deformation or for flation makes it hard to see what values are similar across the map. Our eyes and brains are not good at comparing colors far apart. This is why there is no option for it.

4. If you want continuous tones for angular deformation or for flation anyway, just used the mixed distortion setting. Since one or the other of the distortions is absent, you will get the correct effect.

— daan

[Piotr]

2. Concerning the original complaint: It’s nonsensical to use gradations for mixed angular and areal distortion because, in mixed form, those gradations normally don’t exist. Angular deformation and areal inflation/deflation (“flation”) do not generally follow the same paths. This is why mixed distortion is continuous rather than in gradations. This is also why there is no option for it.

If a person wants the ugly version for mixed, he can just use the rounding to nearest gradiation for both angular and areal implemented in Geocart 4, 3.2, 3.9, 3.5, 5 or whatever the next version will be.

3. Meanwhile, using continuous tones for pure angular deformation or for flation makes it hard to see what values are similar across the map. Our eyes and brains are not good at comparing colors far apart. This is why there is no option for it.

You can just invert the answer above; if a person wants the beautiful version for singular, he can just use the option not to use rounding implemented in next Geocart or Geocart 3.

4. If you want continuous tones for angular deformation or for flation anyway, just used the mixed distortion setting. Since one or the other of the distortions is absent, you will get the correct effect.

— daan

Where is the option to do that for the sample distortion visualization pictures? In the sample distortion visualization pictures, equal-area and compromise projections are impossible to compare.

[Atarimaster]

First off, in my opinion those distortion visualization images are about looking beautiful but about obtaining information about the projection’s distortions.
Thus, by default they should be rendered in a way that lets you obtain the information best. And I fully agree with daan here: Using continuous tones for pure angular or areal distortion is not the best way to evaluate the distortions.

However, if you absolutely want to, there already are two ways to have (more or less) continuous tones for e.g. an equal-area projection. One was mentioned in daan’s last posting, the other one was mentioned in my last posting. So I don’t understand what it is that you want to be added.

If a person wants the ugly version for mixed, he can just use the rounding to nearest gradiation for both angular and areal implemented in Geocart 4, 3.2, 3.9, 3.5, 5 or whatever the next version will be.

Sorry, I don’t understand what you’re saying here (English isn’t my native language, too).

Where is the option to do that for the sample distortion visualization pictures? In the sample distortion visualization pictures, equal-area and compromise projections are impossible to compare.

Okay, you’re right: It is hard to compare e.g. the distortions of an equal-area or a conformal projection with the distortion of a compromise projection in the sample images.
This has never bugged me because if I want to compare them, I just create two maps of the projections in question, and then set the distortion visualization to whatever parameters that I feel to be helpful here.

However, if the sample images were to be changed, I’d prefer them to be the other way round: Leave the samples for equal-area and conformal projections the way they are, and (conformal… no,) compromise projections are displayed with two sample images, namely the "ugly" images, showing areal distortion on one image and angular distortion on the other.
(But as I said, I don’t feel that this is really needed.)

Regards,
Tobias

[Piotr]

I never want gradiations, because they reduce precision.

Also, why does the geographical sample picture of universal Transverse Mercator have a weird amount of detail compared to the default 5400×2700 database?

[Atarimaster]

I never want gradiations, because they reduce precision.

They do, but sometimes reducing precision is needed to obtain information. Especially when you want to obtain information at a glance (e.g. in the "Change Projection" dialogue).
You can’t expect to obtain precise information from a world map of roughly 370px width, anyway…

However, the sample images that you talk about can quite easily be found on your harddisk in Geocart’s macOS version. I don’t know if that is the case in the Windows version, too.
So theoretically, you could replace them on your own system. However, they are in a place that you usually shouldn’t mess with. So while I can’t imagine that Geocart will stop running properly if you replace those images… well, don’t say I didn’t warn you if it does.