Create attributes in rast to store metadata

[fchianucci]

I already noticed here https://stackoverflow.com/questions/71367060/write-rasterstack-and-preserve-metadata-in-r that terra::rast() can store names() and time() attributes, but what about storing additional metadata? Something likes the @DaTa@attributes in raster::raster()

[rhijmans]

It would be possible to allow storing arbitrary metadata. But I am not sure what the value of that would be. Do you have a compelling use-case?

[fchianucci]

Hi Robert, thanks for your reply. As example, I have created an R package to process fisheye images, it consists of 4 functions which sequentially use raster() to process images. After each steps, I stored the metadata of processing in slots like: ***@***.***@attributes$channel <- channel ***@***.***@attributes$stretch <- stretch ***@***.***@attributes$gamma <- gamma where channel, stretch, gamma are examples of function arguments whose information are then carried out to subsequent functions. I would switch from raster::raster() to terra::rast() but I don't know to bring the information among sequential functions using rast(). Any suggestions? F

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On Mon, Oct 9, 2023 at 11:11 AM Robert Hijmans ***@***.***> wrote: It would be possible to allow storing arbitrary metadata. But I am not sure what the value of that would be. Do you have a compelling use-case? — Reply to this email directly, view it on GitHub <#1304 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AGX3WQE33Z6WHHDJVFKL73LX6O5TTAVCNFSM6AAAAAA5VTPVXGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTONJSGYYTIOBSGA> . You are receiving this because you authored the thread.Message ID: ***@***.***>

-- Francesco CHIANUCCI PhD Forest Ecology CREA - Research Center for Forestry and Wood, Arezzo, Italy <https://www.crea.gov.it/en/web/foreste-e-legno> ORcID <http://orcid.org/0000-0002-5688-2060> Skype: checcoar

[rhijmans]

Thanks. Please have a look at tags<- to set arbitrary metadata and tags to get the metadata.

A next step could be to also write and read these tags when using file formats that support arbitrary tags (GeoTiff, not sure if there are others).

[rhijmans]

The tags are now written to file (and read again) when using GeoTiff.

[fchianucci]

Wow. that's great. Many thanks, Francesco

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On Tue, Oct 10, 2023 at 1:53 PM Robert Hijmans ***@***.***> wrote: The tags are now written to file (and read again) when using GeoTiff. — Reply to this email directly, view it on GitHub <#1304 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AGX3WQFAFMKDMNLXSKUHIMLX6UZLRAVCNFSM6AAAAAA5VTPVXGVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTONJVGIYDEOJRHE> . You are receiving this because you authored the thread.Message ID: ***@***.***>

-- Francesco CHIANUCCI PhD Forest Ecology CREA - Research Center for Forestry and Wood, Arezzo, Italy <https://www.crea.gov.it/en/web/foreste-e-legno> ORcID <http://orcid.org/0000-0002-5688-2060> Skype: checcoar

[kadyb]

If anyone is looking for this function, tags() has been renamed to metags().