Regarding negative p-value for raster.kendall

[adeel1997]

Thank you for this great package. I was trying to run Mann Kendall test on the raster stack. While I was looking at the p-value of the output. I am getting negative values and many values greater than 1. I believe there is some issue in it. It would be great if you look into that.

Thanks

[MARIASUAM]

Same here, p-values ranging between -3 and +3. Any hints?

[pachecoferrada]

I'm dealing with the same issue. Any suggestions?

[jeffreyevans]

I need some data in order to reproduce the issue. Can you please provide a single timeseries vector that is producing a negative p-value and make sure that the p-value, and not the z-value is negative? Get Outlook for Android<https://aka.ms/AAb9ysg>

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________________________________ From: pachecoferrada ***@***.***> Sent: Monday, October 25, 2021 9:04:48 AM To: jeffreyevans/spatialEco ***@***.***> Cc: Subscribed ***@***.***> Subject: Re: [jeffreyevans/spatialEco] Regarding negative p-value for raster.kendall (#22) I'm dealing with the same issue. Any suggestions? — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub<#22 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ACLKH7ZBRY7CFA534KK4QULUIVWZBANCNFSM4PV2CNMQ>. Triage notifications on the go with GitHub Mobile for iOS<https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android<https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>.

[MARIASUAM]

Finally I used function MannKendall from package Kendall as I couldn't solve the issue with raster.kendall. The code I used, adapted from code found somewhere else, is:

fun_k <- function(x) {return(unlist(MannKendall(x)))}

kendall_output <- calc(my_stack, fun_k)