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Wind speed graph showing negative speeds

Topics about the Beta trials up to Build 3043, the last build by Cumulus's founder Steve Loft. It was by this time way out of Beta but Steve wanted to keep it that way until he made a decision on his and Cumulus's future.

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freddie
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Wind speed graph showing negative speeds

Post by freddie »

http://www.hosiene.co.uk/weather-test/trends.htm

MX hasn't _recorded_ a negative speed - they just are presented as the lowest value on the graph, which looks a bit odd because it will never happen.
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Re: Wind speed graph showing negative speeds

Post by mcrossley »

It seems it is just the scale that is going negative, the values only go down to zero?

A quick fix is to edit cumuluscharts.js, at line 424 add the line "min: 0," like this...

Code: Select all

        yAxis: [{
                // left
                min: 0,
                title: {text: 'Wind Speed ('+config.wind.units+')'},
freddie
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Re: Wind speed graph showing negative speeds

Post by freddie »

mcrossley wrote:It seems it is just the scale that is going negative, the values only go down to zero?
Yes, that's what I meant. Negative values in this context will not happen, though, so shouldn't appear.
mcrossley wrote:A quick fix is to edit cumuluscharts.js
Thanks - I will try that now.
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Re: Wind speed graph showing negative speeds

Post by steve »

Wind direction and rainfall already have min:0, perhaps I should also do that for some of the others? I don't know if there's any way to specify that the scale should never be negative without fixing the origin at zero. Do people generally prefer graphs which always start at zero, or just show the relevant part? I think pressure has to be the latter, but what about the others?
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Re: Wind speed graph showing negative speeds

Post by freddie »

steve wrote:what about the others?
I vote for showing the origin with wind speed. When you have high speeds you can then see them relative to the origin, and can directly compare to lower speeds. Or, alternatively, vary the origin but have a minimum of zero. Is this possible?
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Re: Wind speed graph showing negative speeds

Post by steve »

freddie wrote:Or, alternatively, vary the origin but have a minimum of zero. Is this possible?
I don't know, that's what I was asking. I'll have a look at the docs tomorrow. But I think I agree that wind speed at least should always start at zero. Even if that means I'll often have a lot of white space on my graph ;) But anyone who wants it otherwise can always modify it themselves; it's just a case of having sensible defaults.
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Re: Wind speed graph showing negative speeds

Post by mcrossley »

steve wrote:[Even if that means I'll often have a lot of white space on my graph ;)
You need a log scale Steve!
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Re: Wind speed graph showing negative speeds

Post by mcrossley »

steve wrote:I don't know if there's any way to specify that the scale should never be negative without fixing the origin at zero.
You can use 'floor:0' for that.
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Re: Wind speed graph showing negative speeds

Post by steve »

Thanks. But I'm thinking that perhaps fixing the wind speed scale at zero is the way to go, and leave all the others as they are (rain and solar are already min:0). Or perhaps also set the humidity graph scale to have min:0? And perhaps also max:100?
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Re: Wind speed graph showing negative speeds

Post by freddie »

steve wrote:Thanks. But I'm thinking that perhaps fixing the wind speed scale at zero is the way to go, and leave all the others as they are (rain and solar are already min:0). Or perhaps also set the humidity graph scale to have min:0? And perhaps also max:100?
I like that - you get consistency of appearance, regardless of range of data in the chart. Each to his own, I guess, but that's the beauty of web-based applications like MX - users can change the appearance to their hearts content (as long as they know how) :-)
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Re: Wind speed graph showing negative speeds

Post by mcrossley »

The way I have done it on my charts is...
Wind, Solar, Rain: all have min:0 and auto max.
Humidity: min:0 max:100
Temperatures, pressure: fully auto, with zero line for temps.

You may also want to think about setting a minRange value to each data type so you avoid charts going from e.g. 0 to 0.1 when there has been no rain etc.
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