[R-sig-Geo] convert from any spatial* classes to a specific character string

[Matteo Mattiuzzi]

 Dear Robin, thanks a lot I have implemented your suggestion: see:
?clmsapi::geo2char Kind regards, Matteo

Am Mi., 2. Sept. 2020 um 17:25 Uhr schrieb Robin Lovelace <rob00x using gmail.com
>:

> Does this help? The approach covers sf, sp and maybe other classes that
> can be converted into sf objects.
>
> ``` r
> library(spData)
> library(sf)
> #> Linking to GEOS 3.8.0, GDAL 3.0.4, PROJ 7.0.0
> x_sf = rmapshaper::ms_simplify(lnd[1:3, ], 0.01)
> #> Registered S3 method overwritten by 'geojsonlint':
> #>   method         from
> #>   print.location dplyr
> x_sp = sf::as_Spatial(x_sf)
> geo_to_char = function(x) {
>   if(!is(object = x, class2 = "sf")) {
>     x = sf::st_as_sf(x)
>   }
>   sf::st_as_text(sf::st_geometry(x))
> }
> geo_to_char(x_sf)
> #> [1] "POLYGON ((-0.3306791 51.32901, -0.3305339 51.34842, -0.3086951
> 51.37545, -0.3177201 51.39367, -0.3096538 51.40001, -0.3060304 51.42123,
> -0.2866189 51.42017, -0.2540906 51.43729, -0.2446848 51.40423, -0.2474248
> 51.39758, -0.2387446 51.38609, -0.2608406 51.37956, -0.2854616 51.36425,
> -0.3039032 51.34325, -0.3057101 51.33541, -0.3193073 51.32781, -0.3306791
> 51.32901))"
>
>
>
> #> [2] "POLYGON ((-0.0785486 51.41985, -0.0689427 51.40418, -0.0427724
> 51.38945, -0.0369519 51.37701, -0.0053322 51.35268, 0.0022661 51.32914,
> -0.0251301 51.33861, -0.0379184 51.33871, -0.0478549 51.32651, -0.0641537
> 51.31863, -0.0848293 51.31587, -0.0943518 51.29936, -0.1243197 51.28676,
> -0.1373403 51.30078, -0.155344 51.30128, -0.1619055 51.31963, -0.1444548
> 51.32648, -0.1475475 51.33878, -0.1275566 51.34745, -0.1169191 51.34575,
> -0.1233396 51.37119, -0.1337986 51.39127, -0.1245223 51.39741, -0.1324811
> 51.40841, -0.1126856 51.42324, -0.0785486 51.41985))"
>
> #> [3] "POLYGON ((0.0022661 51.32914, -0.0053322 51.35268, -0.0369519
> 51.37701, -0.0427724 51.38945, -0.0689427 51.40418, -0.0785486 51.41985,
> -0.0748669 51.4258, -0.0436909 51.42291, -0.0301069 51.42565, -0.0105455
> 51.41355, 0.0254105 51.42899, 0.0398142 51.44099, 0.0585966 51.42459,
> 0.0753431 51.43199, 0.1124939 51.41317, 0.134136 51.41385, 0.1488766
> 51.40848, 0.1598909 51.39465, 0.1498092 51.39087, 0.1532098 51.37804,
> 0.1362526 51.34555, 0.1166538 51.3413, 0.1202182 51.33214, 0.1047428
> 51.32734, 0.0850008 51.31602, 0.0856654 51.29309, 0.0584828 51.28936,
> 0.0457041 51.29401, 0.0328814 51.30752, 0.0149821 51.29179, 0.0022661
> 51.32914))"
> geo_to_char(x_sp)
> #> [1] "POLYGON ((-0.3306791 51.32901, -0.3305339 51.34842, -0.3086951
> 51.37545, -0.3177201 51.39367, -0.3096538 51.40001, -0.3060304 51.42123,
> -0.2866189 51.42017, -0.2540906 51.43729, -0.2446848 51.40423, -0.2474248
> 51.39758, -0.2387446 51.38609, -0.2608406 51.37956, -0.2854616 51.36425,
> -0.3039032 51.34325, -0.3057101 51.33541, -0.3193073 51.32781, -0.3306791
> 51.32901))"
>
>
>
> #> [2] "POLYGON ((-0.0785486 51.41985, -0.0689427 51.40418, -0.0427724
> 51.38945, -0.0369519 51.37701, -0.0053322 51.35268, 0.0022661 51.32914,
> -0.0251301 51.33861, -0.0379184 51.33871, -0.0478549 51.32651, -0.0641537
> 51.31863, -0.0848293 51.31587, -0.0943518 51.29936, -0.1243197 51.28676,
> -0.1373403 51.30078, -0.155344 51.30128, -0.1619055 51.31963, -0.1444548
> 51.32648, -0.1475475 51.33878, -0.1275566 51.34745, -0.1169191 51.34575,
> -0.1233396 51.37119, -0.1337986 51.39127, -0.1245223 51.39741, -0.1324811
> 51.40841, -0.1126856 51.42324, -0.0785486 51.41985))"
>
> #> [3] "POLYGON ((0.0022661 51.32914, -0.0053322 51.35268, -0.0369519
> 51.37701, -0.0427724 51.38945, -0.0689427 51.40418, -0.0785486 51.41985,
> -0.0748669 51.4258, -0.0436909 51.42291, -0.0301069 51.42565, -0.0105455
> 51.41355, 0.0254105 51.42899, 0.0398142 51.44099, 0.0585966 51.42459,
> 0.0753431 51.43199, 0.1124939 51.41317, 0.134136 51.41385, 0.1488766
> 51.40848, 0.1598909 51.39465, 0.1498092 51.39087, 0.1532098 51.37804,
> 0.1362526 51.34555, 0.1166538 51.3413, 0.1202182 51.33214, 0.1047428
> 51.32734, 0.0850008 51.31602, 0.0856654 51.29309, 0.0584828 51.28936,
> 0.0457041 51.29401, 0.0328814 51.30752, 0.0149821 51.29179, 0.0022661
> 51.32914))"
> ```
>
> <sup>Created on 2020-09-02 by the [reprex package](
> https://reprex.tidyverse.org) (v0.3.0)</sup>
>
> On Wed, Sep 2, 2020 at 1:25 PM Matteo Mattiuzzi <matteo using mattiuzzi.com>
> wrote:
>
>> Dear list,
>>
>> I have recently submitted a little R package to CRAN (now waiting for
>> approval) https://github.com/MatMatt/clmsapi.
>> The package is a R client for downloading data from the Copernicus Land
>> Monitoring Service (https://cryo.land.copernicus.eu/finder/).
>>
>> The API expects a parameter called 'geometry' with the following
>> formatting
>> (character):
>> 'POLYGON((lon+lat,lon+lat,lon+lat, ... ))' # commas are replaced with
>> ascii
>> '%2C' in the query string
>> or
>> 'POINT(lon+lat)'
>> see also here:
>> https://cryo.land.copernicus.eu/resto/api/collections/HRSI/describe.xml
>>
>> I could expect users to prepare the geometry parameter as it is needed by
>> the API, but I would prefer to improve the user friendliness by adding
>> some
>> functionalities (similar as in the MODIS package) that can convert from
>> different spatial extent objects/classes to the needed character string
>> (in
>> clmsapi::composeUrl).
>>
>> What is the best way to implement that? What are the classes I should
>> consider as input for the geometry parameter? (i.e. well established and
>> well supplied with conversion-functions).
>>
>> Thanks and kind regards, Matteo
>>
>>         [[alternative HTML version deleted]]
>>
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>>
>

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