Displaying 20 results from an estimated 1000 matches similar to: "How to produce rainfall maps"
2017 Nov 21
0
How to produce rainfall maps
Hi,
You might get more help from the R-sig-geo list, which is devoted to
spatial topics.
However.
The *.asc file is an ArcGIS raster export format. You should use
whatever the appropriate import commands are for your own gridded
rainfall data. If you have a different format, you might or might not
be able to import it directly with raster.
?raster will tell you more about the kinds of formats
2017 Nov 22
2
How to produce rainfall maps
Fwiw the engine behind geom_raster needs explicit observation-per-row form
for input (with no structural normalization), so conversion to points is
perfectly proper here, albeit confusing in context. (It's closer to what
graphics devices actually use ultimately, but the expansion is laid out
very early in ggplot2 because there's no standard for intermediate forms.)
Cheers, Mike
On Wed,
2017 Nov 23
0
How to produce rainfall maps
Thank you Sarah and Mike for your explanations.
My final objective is to produce maps (png image or any kind of extension I can import in LaTeX) where rainfall data are interpolated, using the Inverse Distance method or Kriging.
My input file (pointfile.csv in the reported example) reports the station code, lat and long of the meteorological station and the rainfall value (which might be the
2018 Mar 21
5
Sum of columns of a data frame equal to NA when all the elements are NA
Dear list users,
let me ask you this trivial question. I worked on that for a long time, by now.
Suppose to have a data frame with NAs and to sum some columns with rowSums:
df <- data.frame(A = runif(10), B = runif(10), C = rnorm(10))
df[1, ] <- NA
rowSums(df[ , which(names(df) %in% c("A","B"))], na.rm=T)
If all the elements of the selected columns are NA, rowSums
2018 Mar 21
0
Sum of columns of a data frame equal to NA when all the elements are NA
On 21/03/2018 11:44 AM, Stefano Sofia wrote:
> Dear list users,
> let me ask you this trivial question. I worked on that for a long time, by now.
> Suppose to have a data frame with NAs and to sum some columns with rowSums:
>
> df <- data.frame(A = runif(10), B = runif(10), C = rnorm(10))
> df[1, ] <- NA
> rowSums(df[ , which(names(df) %in%
2018 Mar 21
3
Sum of columns of a data frame equal to NA when all the elements are NA
What do you mean by "should not"?
NULL means "missing object" in R. The result of the sum function is always expected to be numeric... so NA_real or NA_integer could make sense as possible return values. But you cannot compute on NULL so no, that doesn't work.
See the note under the "Value" section of ?sum as to why zero is returned when all inputs are removed.
2024 May 28
1
add only the 1st of May with POSIXct
?s 16:23 de 28/05/2024, Stefano Sofia escreveu:
> Dear R-list users,
>
> From an initial and a final date I create a sequence of days using POSIXct.
>
> If this interval covers all or only in part the months from May to October, I need to get rid of the days from the 2nd of May to the 31st of October:
>
>
> a <- as.POSIXct("2002-11-01", format =
2024 May 29
1
add only the 1st of May with POSIXct
Thank you Rui for your code.
I basically understood all your suggestions.
I am using an old version of R (version 3.6.3, installed in a server I am not allowed to control), and the new pipe operator does not work.
I tried to run your code without the "|>" operator, but I get an error when I use apply.
Could you please expand your code without the pipe operator?
Thank you again
2023 May 13
2
aggregate wind direction data with wind speed required
Dear list users,
I have to aggregate wind direction data (wd) using a function that requires also a second input variable, wind speed (ws).
This is the function that I need to use:
my_fun <- function(wd1, ws1){
u_component <- -ws1*sin(2*pi*wd1/360)
v_component <- -ws1*cos(2*pi*wd1/360)
mean_u <- mean(u_component, na.rm=T)
mean_v <- mean(v_component, na.rm=T)
mean_wd
2018 Mar 21
2
Sum of columns of a data frame equal to NA when all the elements are NA
No. The empty sum is zero. Adding it to another sum should not change it. Nothing audacious about that. This is consistent; other definitions just cause trouble.
-pd
> On 21 Mar 2018, at 18:05 , Boris Steipe <boris.steipe at utoronto.ca> wrote:
>
> Surely the result of summation of non-existent values is not defined, is it not? And since the NA values have been _removed_,
2018 Mar 21
0
Sum of columns of a data frame equal to NA when all the elements are NA
Should not the result be NULL if you have removed the NA with na.rm=TRUE ?
B.
> On Mar 21, 2018, at 11:44 AM, Stefano Sofia <stefano.sofia at regione.marche.it> wrote:
>
> Dear list users,
> let me ask you this trivial question. I worked on that for a long time, by now.
> Suppose to have a data frame with NAs and to sum some columns with rowSums:
>
> df <-
2018 Mar 21
0
Sum of columns of a data frame equal to NA when all the elements are NA
Surely the result of summation of non-existent values is not defined, is it not? And since the NA values have been _removed_, there's nothing left to sum over. In fact, pretending the the result in that case is zero would appear audacious, no?
Cheers,
Boris
> On Mar 21, 2018, at 12:58 PM, Jeff Newmiller <jdnewmil at dcn.davis.ca.us> wrote:
>
> What do you mean by
2024 May 29
1
add only the 1st of May with POSIXct
On Tue, 28 May 2024, Stefano Sofia writes:
> Dear R-list users,
>
> From an initial and a final date I create a sequence of days using POSIXct.
>
> If this interval covers all or only in part the months from May to October, I need to get rid of the days from the 2nd of May to the 31st of October:
>
>
> a <- as.POSIXct("2002-11-01", format =
2024 May 28
2
add only the 1st of May with POSIXct
Dear R-list users,
>From an initial and a final date I create a sequence of days using POSIXct.
If this interval covers all or only in part the months from May to October, I need to get rid of the days from the 2nd of May to the 31st of October:
a <- as.POSIXct("2002-11-01", format = "%Y-%m-%d", tz="Etc/GMT-1")
b <- as.POSIXct("2004-06-01",
2006 Feb 09
3
about Cox-Box transformation
Dear R-users,
I am using R version 1.8.0-1 under Suse 8.2.
I need to use the boxcox command because I want to apply a Cox-Box
transformation to a vector of rainfall values.
Within the libraries, the MASS library is present, but I don't know
whether this means that is automatically installed or not.
The command doesn't work. What do I have to do in order to make it
working? Is just a
2018 Mar 21
0
Sum of columns of a data frame equal to NA when all the elements are NA
I see: consistency with additive identity. That makes sense. Thanks.
B.
> On Mar 21, 2018, at 1:22 PM, peter dalgaard <pdalgd at gmail.com> wrote:
>
> No. The empty sum is zero. Adding it to another sum should not change it. Nothing audacious about that. This is consistent; other definitions just cause trouble.
>
> -pd
>
>> On 21 Mar 2018, at 18:05 , Boris
2023 May 13
1
aggregate wind direction data with wind speed required
?s 15:51 de 13/05/2023, Stefano Sofia escreveu:
> Dear list users,
>
> I have to aggregate wind direction data (wd) using a function that requires also a second input variable, wind speed (ws).
>
> This is the function that I need to use:
>
>
> my_fun <- function(wd1, ws1){
>
> u_component <- -ws1*sin(2*pi*wd1/360)
> v_component <-
2018 Mar 21
1
Sum of columns of a data frame equal to NA when all the elements are NA
"I see: consistency with additive identity. "
Ummm, well:
> 1+NULL
numeric(0)
> sum(1,NULL)
[1] 1
Of course, there could well be something here I don't get, but that doesn't
look very consistent to me. However, as I said privately, so long as the
corner case behavior is documented, which it is, I don't care.
Cheers,
Bert
Bert Gunter
"The trouble with
2013 Apr 02
2
Create a vector without using an external 'if statement'
Dear R-users,
suppose I have three dataframes like these
df1:
mydate min_temp
31032013 12
01042013 8
02042013 -999
df2:
mydate min_temp
31032013 10
01042013 11
02042013 14
df3:
mydate min_temp
31032013 4
01042013 3
02042013 5
where -999 means that the temperature data is not available (at the moment I cannot change it to NA because I am not the db administrator);
suppose also that oggi is
2017 Jun 16
2
point size
Hi all;
I am running the following ggplot codes. Runs well. However, I need to
reflect the numeric values of the log10_P to the point size in the graph.
Your help highly appreciated,
Regards,
Greg
p <- ggplot(mydata, aes(x = X, y = log10_P)) +
theme_bw() +theme(panel.border=element_blank())
+ theme(legend.position="top", axis.text=element_text(size = 8))
(p1 <- p +