[Qgis-user] z factor

[Raymond Nijssen]

Hi Nicolas,

It is just a simple formula for calculating the "z-factor" for a given 
latitude. What would that look like in a plugin? Where would it go? What 
would it do or show?

Last week I had a similar idea for a plugin that could tell you which 
UTM zone to pick for your current canvas. I decided it would not be 
worth the effort. But maybe these could go together (and be finished at 
the end of this "KwakFriday"?

Regards,
Raymond


On 27-11-2020 06:13, Nicolas Cadieux wrote:
> Hi,
> 
> It's just the Z factor needed when you make a hillshade when the x an y 
> are in degrees and the z is in feet or meters (like SRTM). You can see 
> it if you choose Hillshade under symbology / render type (for a raster 
> layer).  It's basically the length of a degree in meters for latitude.
> 
> https://www.esri.com/arcgis-blog/products/product/imagery/setting-the-z-factor-parameter-correctly/ 
> 
> 
> Nicolas
> 
> On 2020-11-27 12:08 a.m., Richard Duivenvoorde wrote:
>> On 11/27/20 5:28 AM, Nicolas Cadieux wrote:
>>> I want to learn to make a QGIS plugin and I was wondering if anybody 
>>> new if there is a QGIS plugin or tool that calculates the z factor 
>>> for a particular latitude? I thought this would be an easy project to 
>>> start with but I don't want to duplicate someone else's work.
>> Hi Nicolas,
>>
>> What do you mean with "calculates the z factor for a particular 
>> latitude"?
>>
>> - z-factor as in x,y,z?
>> - Do you mean based on a crs/datum? So more proj-based?
>> - Or do you mean based on a known dataset with not enough z-info? So 
>> more extra/intrapolation?
>> - Raster? Vector?
>> - Creating a new dataset (processing)? Or just reporting for one lat 
>> (desktop/gui)?
>>
>> Just trying to get an idea of your idea :-)
>>
>> Regards,
>>
>> Richard Duivenvoorde
>>
>>
>>