Most wanted features that ZyGrib misses.

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Fliers
Posts: 8
Joined: 05 Jan 2014 16:55

Most wanted features that ZyGrib misses.

Post by Fliers » 05 Jan 2014 17:16

Hi,

ZyGrib is an EXCELLENT program but misses 1 feature that is very useful.
The ability of controlling the scale and colors of the legend and the map. What i mean?

Consider the following map where the temperatures of the level on 700 hPa is shown.
Image

Everything seems the same! Every area seems to have almost the same temperature and that is because the scale is constant no matter what temperatures are on the map. Here the temperatures range from -10 to -4 but because the scale is constant and ranges between -50 to 50, the change of shade in colors from -4 to -10 is very small and when you have a map like this with only -10 to -4 temperatures, it is very difficult to distinguish between the colors and all areas seem to have the same temperature(color)!

My wish is zyGrib to add the feature to be able to manually change the scale and the color.
So here for example, to put the color ███ as -4 and the color ███ as -10 so the map would be much clearer and someone could much easier to distinguish the temperature distributions in the area.

This is particularly useful in precipitation maps(not that in temperature/wind etc maps is not useful. It is very useful also!)!! Where now the amount of precipitation seems to be at every map about the same! So for example in zyGrib you see that:
Image

And what i'm suggesting would make it something like this:
Image

Much clearer picture of where heavier precipitation will occur.

That's why my suggestion is to:
a)Be able to set manually the maximum seen value(e.g 2 mm/h or 8°C) and the minimum observed value of the map(e.g 0 mm/h or -4°C). Or even better the program to identify the max/min and put them itself.
b)Be able to set the scale(the STEP) between these 2 values(MAX,MIN), i.e the number of different colors to appear, example the color to change every 0.5 mm/h or 1 °C (so for example to set min=+4 °C, max=+10 °C with step +1 °C so 7 colors to be used).
c)Be able to set the color of the minimum and the maximum values(with an RGB picker for example) and in-between the program to fill the gaps with colors from the visible light spectrum for example, with a discrete numbers of colors of course and equal to: number of colors = (MAX-MIN)/STEP +1


The other feature i would like to see, and i don't know why it doesn't exist, is to be able to see the GFS run beyond 8 days and up to 384 hours(16 days) as it is also freely available.


I hope my suggestions would be considered and i wish i will see them in the next update. :mrgreen:

jza
Site Admin
Posts: 600
Joined: 19 Jan 2009 00:22

Re: Most wanted features that ZyGrib misses.

Post by jza » 07 Jan 2014 08:54

Hi,

You can create your own color scales.
Files are in the directory data/colors (do not change the file names).
Format is very crude : one line "value red green blue" per data value in an ascending order.

Some color scales are not linear, so it is difficult to do an automatic generation.

When you are happy, you can submit beautiful color maps. ;)
A+
Jacques

Fliers
Posts: 8
Joined: 05 Jan 2014 16:55

Re: Most wanted features that ZyGrib misses.

Post by Fliers » 07 Jan 2014 12:05

jza wrote:Hi,

You can create your own color scales.
Files are in the directory data/colors (do not change the file names).
Format is very crude : one line "value red green blue" per data value in an ascending order.

Some color scales are not linear, so it is difficult to do an automatic generation.

When you are happy, you can submit beautiful color maps. ;)
Very interesting, thanks. :)

What about this:
The other feature i would like to see, and i don't know why it doesn't exist, is to be able to see the GFS run beyond 8 days and up to 384 hours(16 days) as it is also freely available.

jza
Site Admin
Posts: 600
Joined: 19 Jan 2009 00:22

Re: Most wanted features that ZyGrib misses.

Post by jza » 07 Jan 2014 20:31

Fliers wrote: The other feature i would like to see, and i don't know why it doesn't exist, is to be able to see the GFS run beyond 8 days and up to 384 hours(16 days) as it is also freely available.
A few year ago, in 2009 (pfff), I answered thet to the same question on this forum: "I know, these data are available on NOAA server, but for my part I prefer to play dice. It's even more reliable for weather forecast and more fun."
The download limit was 7 days.

In 2011, GFS model has become a little more reliable, so the limit has been extended to 8 days.

In 2014, I suppose the quality of the model was even better a bit, but I prefer to wait analyzes performance of year 2013 before taking a decision.
In addition, the file server is much more powerful than in 2009 and it can absorb a greater load. So ... maybe ... we'll see ...
A+
Jacques

Fliers
Posts: 8
Joined: 05 Jan 2014 16:55

Re: Most wanted features that ZyGrib misses.

Post by Fliers » 07 Jan 2014 22:42

jza wrote:A few year ago, in 2009 (pfff), I answered thet to the same question on this forum: "I know, these data are available on NOAA server, but for my part I prefer to play dice. It's even more reliable for weather forecast and more fun."
The download limit was 7 days.

In 2011, GFS model has become a little more reliable, so the limit has been extended to 8 days.

In 2014, I suppose the quality of the model was even better a bit, but I prefer to wait analyzes performance of year 2013 before taking a decision.
In addition, the file server is much more powerful than in 2009 and it can absorb a greater load. So ... maybe ... we'll see ...
You are very much correct about this of course but my opinion is just give the option to the user and let the user to get troubled and think of their credibility. :) Also do not forget zyGrib is not only about forecasts but is is also a SUPERB meteorological tool so an interesting map beyond 8 days could not be studied in zyGrib's superb environment. :(

On the other hand you can always think of implementing the ensembles forecasts also. :mrgreen: It's called GEFS and it consists of 21 members and it's totally free also. It's much more reliable from the main run of GFS for forecasts of more than 5-6 days.
Just an idea.

By the way the source code of zyGrib is freely available right? In what language is coded? C, C++, Fortran, or something else?

boby786
Posts: 1
Joined: 06 Feb 2014 10:21

Re: Most wanted features that ZyGrib misses.

Post by boby786 » 06 Feb 2014 10:24

Everything seems the same! Every area seems to have almost the same temperature and that is because the scale is constant no matter what temperatures are on the map. Here the temperatures range from -10 to -4 but because the scale is constant and ranges between -50 to 50, the change of shade in colors from -4 to -10 is very small and when you have a map like this with only -10 to -4 temperatures, it is very difficult to distinguish between the colors and all areas seem to have the same temperature(color)!
Boby

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