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Jonsson

Min , Max

Hellow everyone,
This code bellow will calculate average daily wind speed(measurements are taken every three hours).Any ideas how to take the Min and Max instead of average.

library(Matrix)
setwd("C:\\Users\\aalyaari\\Desktop\\img")
listfile<-dir()
long <- file("C:\\Users\\aalyaari\\Desktop\\New folder (5)\\inra.bin", "rb")
A=readBin(long, integer(), size=2,n=67420*1, signed=F)
ta<-t(A)
lot <- file("C:\\Users\\aalyaari\\Desktop\\New folder (5)\\lat.img", "rb")
B=readBin(lot, integer(), size=2,n=67420*1, signed=F)
tb<-t(B)

for (n in 1:length(listfile))
{

#h[n]=listfile[n]
h=listfile[n]
#b[n]=file.info(h[n])$size/67420/4
b=file.info(h[n])$size/67420/4

wind <- file(h, "rb")
C=readBin(wind, double(), size=4,n=67420*b, signed=TRUE)

D<-matrix(C,nrow=b,ncol=67420)

for(d in 1:b)
{
M <- Matrix(-9999, 360, 720)
tm<-t(M)
for(i in 1:67420)
{
tm[ta[i],tb[i]]= round(10 * ((D[(d-1)*8+1,i] + D[(d-1)*8+2,i] +D[(d-1)*8+3,i] +D[(d-1)*8+4,i] +D[(d-1)*8+5,i] +D[(d-1)*8+6,i] +D[(d-1)*8+7,i] +D[(d-1)*8+8,i] ) / 8))

}
to.write <- sprintf("C:\\Users\\aalyaari\\Desktop\\New folder (6)\\Yar_%00d.bin", d)
writeBin(as.integer(tm@x), size=2,to.write)
}
}

Rui Barradas

Re: Min , Max

Hello,

Jonsson wrote

Hellow everyone,
This code bellow will calculate average daily wind speed(measurements are taken every three hours).Any ideas how to take the Min and Max instead of average.

library(Matrix)
setwd("C:\\Users\\aalyaari\\Desktop\\img")
listfile<-dir()
long <- file("C:\\Users\\aalyaari\\Desktop\\New folder (5)\\inra.bin", "rb")
A=readBin(long, integer(), size=2,n=67420*1, signed=F)
ta<-t(A)
lot <- file("C:\\Users\\aalyaari\\Desktop\\New folder (5)\\lat.img", "rb")
B=readBin(lot, integer(), size=2,n=67420*1, signed=F)
tb<-t(B)

for (n in 1:length(listfile))
{

#h[n]=listfile[n]
h=listfile[n]
#b[n]=file.info(h[n])$size/67420/4
b=file.info(h[n])$size/67420/4

wind <- file(h, "rb")
C=readBin(wind, double(), size=4,n=67420*b, signed=TRUE)

D<-matrix(C,nrow=b,ncol=67420)

for(d in 1:b)
{
M <- Matrix(-9999, 360, 720)
tm<-t(M)
for(i in 1:67420)
{
tm[ta[i],tb[i]]= round(10 * ((D[(d-1)*8+1,i] + D[(d-1)*8+2,i] +D[(d-1)*8+3,i] +D[(d-1)*8+4,i] +D[(d-1)*8+5,i] +D[(d-1)*8+6,i] +D[(d-1)*8+7,i] +D[(d-1)*8+8,i] ) / 8))

}
to.write <- sprintf("C:\\Users\\aalyaari\\Desktop\\New folder (6)\\Yar_%00d.bin", d)
writeBin(as.integer(tm@x), size=2,to.write)
}
}

Your code line with 'round', near the bottom, is equivalent to this simpler line:

tm[ta[i],tb[i]]= round(10 * sum(D[(d-1)*8 + 1:8, i]) / 8)

Note that this doesn't give the average, but the average multiplied by 10.
For the average, with and without the factor 10, use

tm[ta[i],tb[i]]= round(10 * mean(D[(d-1)*8 + 1:8, i]))
tm[ta[i],tb[i]]= round(mean(D[(d-1)*8 + 1:8, i]))

(Why not use the parameter 'digits'?)
tm[ta[i],tb[i]]= round(mean(D[(d-1)*8 + 1:8, i]), 1)

Now just substitute min or max for mean.

Hope this helps,

Rui Barradas

Jonsson

Re: Min , Max

Dear Rui,

I really appreciate your help. This is exactly what I was looking for.I know there is simpler way than mine but I couldn't figure it out.So, many many thanks.

I wonder what is the difference between

This: tm[ta[i],tb[i]]= round(mean(D[(d-1)*8 + 1:8, i]))
and This: (Why not use the parameter 'digits'?)
tm[ta[i],tb[i]]= round(mean(D[(d-1)*8 + 1:8, i]), 1)

Michael Weylandt

Re: Min , Max

In reply to this post by Jonsson

You might want to look into the caTools package: it provides runmean,
runmin, and runmax functions -- if you set those for a window of
length 8 and then take every 8th element, you should get what you're
looking for (much cleaner and faster too!) A good way to do that
subset is something like:

x <- 1:100
y <- x^2 - 3*x + 5
n <- 8

y[!(seq_along(x) %% n)]

Though I'm pretty sure I've seen a cleaner version elsewhere....

Michael

On Fri, Apr 27, 2012 at 11:46 AM, Jonsson <[hidden email]> wrote:

> Hellow everyone,
> This code bellow will calculate average daily wind speed(measurements are
> taken every three hours).Any ideas how to take the Min and Max instead of
> average.
>
> library(Matrix)
> setwd("C:\\Users\\aalyaari\\Desktop\\img")
> listfile<-dir()
> long <- file("C:\\Users\\aalyaari\\Desktop\\New folder (5)\\inra.bin", "rb")
> A=readBin(long, integer(), size=2,n=67420*1, signed=F)
> ta<-t(A)
> lot <- file("C:\\Users\\aalyaari\\Desktop\\New folder (5)\\lat.img", "rb")
> B=readBin(lot, integer(), size=2,n=67420*1, signed=F)
> tb<-t(B)
>
> for (n in 1:length(listfile))
> {
>
> #h[n]=listfile[n]
> h=listfile[n]
> #b[n]=file.info(h[n])$size/67420/4
> b=file.info(h[n])$size/67420/4
>
> wind <- file(h, "rb")
> C=readBin(wind, double(), size=4,n=67420*b, signed=TRUE)
>
> D<-matrix(C,nrow=b,ncol=67420)
>
> for(d in 1:b)
> {
> M <- Matrix(-9999, 360, 720)
> tm<-t(M)
> for(i in 1:67420)
> {
> tm[ta[i],tb[i]]= round(10 * ((D[(d-1)*8+1,i] + D[(d-1)*8+2,i]
> +D[(d-1)*8+3,i] +D[(d-1)*8+4,i] +D[(d-1)*8+5,i] +D[(d-1)*8+6,i]
> +D[(d-1)*8+7,i] +D[(d-1)*8+8,i] ) / 8))
>
> }
> to.write <- sprintf("C:\\Users\\aalyaari\\Desktop\\New folder
> (6)\\Yar_%00d.bin", d)
> writeBin(as.integer(tm@x), size=2,to.write)
> }
> }
>
>
> --
> View this message in context: http://r.789695.n4.nabble.com/Min-Max-tp4593065p4593065.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> [hidden email] mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

______________________________________________
[hidden email] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Rui Barradas

Re: Min , Max

In reply to this post by Jonsson

Hello,

Jonsson wrote

Dear Rui,

I really appreciate your help. This is exactly what I was looking for.I know there is simpler way than mine but I couldn't figure it out.So, many many thanks.

I wonder what is the difference between

This: tm[ta[i],tb[i]]= round(mean(D[(d-1)*8 + 1:8, i]))
and This: (Why not use the parameter 'digits'?)
tm[ta[i],tb[i]]= round(mean(D[(d-1)*8 + 1:8, i]), 1)

round defaults to 0 decimal places. The second version uses 1, just as an example.
From the help page:
"round rounds the values in its first argument to the specified number of decimal places (default 0). "

See
?round

Rui Barradas

Jonsson

Re: Min , Max

The piece of R code given above is meant to perform calculations for many files(12) in one folder.But I am getting this error:Error: subscript out of bounds.It finished reading the first file(successfully) but the error arose when it started to read the next file. Any suggestions why?. I think the problem is in this first loop: for (n in 1:length(listfile)) { h=listfile[n]
b=file.info(h[n])$size/67420/4

Michael Weylandt

Re: Min , Max

Just a total guess but if h is the n-th element of listfile, do you
really mean to be taking the n-th element of h as well? It could be
that when you get to the second element h[n] becomes h[2] which
doesn't exist (h[1] obviously did)

If you do mean this, listfile is probably a list (possibly of lists)
so you want listfile[[n]] to get the n-th element (rather than a
sublist)

Hope this helps,
Michael

On Fri, Apr 27, 2012 at 1:28 PM, Jonsson <[hidden email]> wrote:

> The piece of R code given above is meant to perform calculations for many
> files(12) in one folder.But I am getting this error:Error: subscript out of
> bounds.It finished reading the first file(successfully) but the error arose
> when it started to read the next file. Any suggestions why?. I think the
> problem is in this first loop: for (n in 1:length(listfile)) { h=listfile[n]
> b=file.info(h[n])$size/67420/4
>
> --
> View this message in context: http://r.789695.n4.nabble.com/Min-Max-tp4593065p4593279.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> [hidden email] mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

Jonsson

Re: Min , Max

Yes this what I meant. I think no need for this line h=listfile[[n]],if I can just put it directly in the other line to do the calculations for every file in my list.they are not really elements.they are files.
what I need is just this:get the size of each file in my list then /67420/4,to get the number of rows and assign that to b . so now b will be used later as a loop.

I tried this also:
for (n in 1:length(listfile)).{
h=listfile[[n]]
b=file.info(h[[n]])$size/67420/4
}
then I got this :Error in h[[n]] : subscript out of bounds

Jonsson

Re: Min , Max

In reply to this post by Michael Weylandt

this is what happened with me:that when I get to the second element h[n] becomes h[2] which
doesn't exist (h[1] obviously did).
Any suggestions

Jonsson

Re: Min , Max

In reply to this post by Michael Weylandt

this is what happened with me:that when I get to the second element h[n] becomes h[2] which
doesn't exist (h[1] obviously did).
Any suggestions

Jeff Newmiller

Re: Min , Max

a) don't double post
b) provide context... the majority of R-helpers do not use nabble
c) read and believe the error message... don't subscript on a vector known to have one element.
---------------------------------------------------------------------------
Jeff Newmiller The ..... ..... Go Live...
DCN:<[hidden email]> Basics: ##.#. ##.#. Live Go...
Live: OO#.. Dead: OO#.. Playing
Research Engineer (Solar/Batteries O.O#. #.O#. with
/Software/Embedded Controllers) .OO#. .OO#. rocks...1k
---------------------------------------------------------------------------
Sent from my phone. Please excuse my brevity.

Jonsson <[hidden email]> wrote:

>this is what happened with me:that when I get to the second element
>h[n]
>becomes h[2] which
>doesn't exist (h[1] obviously did).
>Any suggestions
>
>--
>View this message in context:
>http://r.789695.n4.nabble.com/Min-Max-tp4593065p4593402.html
>Sent from the R help mailing list archive at Nabble.com.
>
>______________________________________________
>[hidden email] mailing list
>https://stat.ethz.ch/mailman/listinfo/r-help
>PLEASE do read the posting guide
>http://www.R-project.org/posting-guide.html
>and provide commented, minimal, self-contained, reproducible code.

Michael Weylandt

Re: Min , Max

In reply to this post by Jonsson

Yes, like I said, you don't need to be subsetting h:

h = listoffiles[n]

then later just use h

Michael

On Fri, Apr 27, 2012 at 2:22 PM, Jonsson <[hidden email]> wrote:

> this is what happened with me:that when I get to the second element h[n]
> becomes h[2] which
> doesn't exist (h[1] obviously did).
> Any suggestions
>
> --
> View this message in context: http://r.789695.n4.nabble.com/Min-Max-tp4593065p4593402.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> [hidden email] mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

Jonsson

Re: Min , Max

In reply to this post by Michael Weylandt

This code bellow will calculate average daily wind speed(measurements are taken every three hours).

library(Matrix)
setwd("C:\\Users\\aalyaari\\Desktop\\img")
listfile<-dir()
long <- file("C:\\Users\\aalyaari\\Desktop\\New folder (5)\\inra.bin", "rb")
A=readBin(long, integer(), size=2,n=67420*1, signed=F)
ta<-t(A)
lot <- file("C:\\Users\\aalyaari\\Desktop\\New folder (5)\\lat.img", "rb")
B=readBin(lot, integer(), size=2,n=67420*1, signed=F)
tb<-t(B)

for (n in 1:length(listfile))
{

#h[n]=listfile[n]
h=listfile[n]
#b[n]=file.info(h[n])$size/67420/4
b=file.info(h[n])$size/67420/4

wind <- file(h, "rb")
C=readBin(wind, double(), size=4,n=67420*b, signed=TRUE)

D<-matrix(C,nrow=b,ncol=67420)

for(d in 1:b)
{
M <- Matrix(-9999, 360, 720)
tm<-t(M)
for(i in 1:67420)
{
tm[ta[i],tb[i]]= round(10 * mean(D[(d-1)*8 + 1:8), i])

}
to.write <- sprintf("C:\\Users\\aalyaari\\Desktop\\New folder (6)\\Yar_%00d.bin", d)
writeBin(as.integer(tm@x), size=2,to.write)
}
}

the values are measured in kelvin so i want to convert them to degree,therefor I want to subtract all values by 273.15 before talking the average or max.... but did not work.In other words, i want this: every value is subtracted by 273.15 first ,then do other calculations(Min, Max)Can anyone tell me what is wrong.Thanks

tm[ta[i],tb[i]]= round(10 * mean(D[((d-1)*8 + 1:8)-273.15), i]))

Rui Barradas

Re: Min , Max

Hello,

>
> i want this: every value is subtracted by 273.15 first ,then do other
> calculations(Min, Max)Can anyone tell me what is wrong.Thanks
>
You're subtracting 273.15 to the row numbers, not to the values in those rows.
Corrected:

d.rows <- (d-1)*8 + 1:8
tm[ta[i],tb[i]]= round(10 * mean(D[d.rows, i] - 273.15))

Note that the d.rows extra variable is not really needed, it's there just for clarity.

Rui Barradas

David Winsemius

Re: Min , Max

In reply to this post by Jonsson

On Apr 28, 2012, at 9:54 AM, Jonsson wrote:

> This code bellow will calculate average daily wind
> speed(measurements are
> taken every three hours).
>
snipped overly complex code not needed to address the semantic error
below.

> the values are measured in kelvin so i want to convert them to
> degree,therefor I want to subtract all values by 273.15 before
> talking the
> average or max.... but did not work.In other words, i want this:
> every value
> is subtracted by 273.15 first ,then do other calculations(Min, Max)Can
> anyone tell me what is wrong.Thanks
>
> tm[ta[i],tb[i]]= round(10 * mean(D[((d-1)*8 + 1:8)-273.15), i])) #
> wrong

You should not be subtracting the temperature offset within the index
if your goal was to subtract the same number from each value in a
matrix. Move it outside the index/extract function. You didn't get an
error from "[" because it automatically truncated the floating point
numbers you were passingwhich should have been integer vectors.

tm[ta[i],tb[i]]= round(10 * mean(D[((d-1)*8 + 1:8)-273.15),
i]-273.15))

(No effort made to check for the sensibility of the assignment to the
'tm' matrix.)

Note:
c(1,2)[2.5]
#[1] 2 No error .... or even a warning.

>
> --
> View this message in context: http://r.789695.n4.nabble.com/Min-Max-tp4593065p4594774.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> [hidden email] mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

David Winsemius, MD
West Hartford, CT

______________________________________________
[hidden email] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Jonsson

Re: Min , Max

Dear David, I think you meant tm[ta[i],tb[i]]= round(10 * mean(D[((d-1)*8 + 1:8),i]-273.15)) not tm[ta[i],tb[i]]= round(10 * mean(D[((d-1)*8 + 1:8)-273.15), i]-273.15)) .

As you can see in the code above.I want to save the results as integer(16bit) thats why I multiplied by 10(as factor),in order to keep one dice-mil . Because I will later divide by 10.for example if I got 25 so this means 2.5. Thats why I used round.

Jonsson

Re: Min , Max

In reply to this post by Michael Weylandt

Hello again,
I am still having the same problem with the main loop.it succeeded to finish reading and writing from the first file in my listfile but failed when it moves to the second file giving this error:Error: subscript out of bounds

library(Matrix)
setwd("C:\\Users\\aalyaari\\Desktop\\img")
listfile<-dir()
long <- file("C:\\Users\\aalyaari\\Desktop\\New folder (5)\\inra.bin", "rb")
A=readBin(long, integer(), size=2,n=67420*1, signed=F)
ta<-t(A)
lot <- file("C:\\Users\\aalyaari\\Desktop\\New folder (5)\\lat.img", "rb")
B=readBin(lot, integer(), size=2,n=67420*1, signed=F)
tb<-t(B)

for (n in 1:length(listfile))
{

h=listfile[n]

b=file.info(h)$size/67420/4

wind <- file(h, "rb")
C=readBin(wind, double(), size=4,n=67420*b, signed=TRUE)

D<-matrix(C,nrow=b,ncol=67420)

for(d in 1:b)
{
M <- Matrix(-9999, 360, 720)
tm<-t(M)
for(i in 1:67420)
{
tm[ta[i],tb[i]]= round(10 * mean(D[(d-1)*8 + 1:8), i])

}
to.write <- sprintf("C:\\Users\\aalyaari\\Desktop\\New folder (6)\\Yar_%00d.bin", d)
writeBin(as.integer(tm@x), size=2,to.write)
}
}

David Winsemius

Re: Min , Max

In reply to this post by Jonsson

On Apr 28, 2012, at 11:51 AM, Jonsson wrote:

> Dear David, I think you meant

tm[ta[i],tb[i]]= round(10 * mean(D[((d-1)*8 + 1:8),i]-273.15)) not

tm[ta[i],tb[i]]= round(10 * mean(D[((d-1)*8 + 1:8)-273.15),
i]-273.15)) .
>
> As you can see in the code above.I want to save the results as
> integer(16bit) thats why I multiplied by 10(as factor),in order to
> keep one
> dice-mil . Because I will later divide by 10.for example if I got 25
> so this
> means 2.5. Thats why I used round.

Yes that is what I meant.

--
David Winsemius, MD
Heritage Laboratories
West Hartford, CT

______________________________________________
[hidden email] mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Rui Barradas

Re: Min , Max

In reply to this post by Jonsson

Hello,

>
> Hello again,
> I am still having the same problem with the main loop.it succeeded to finish reading and writing from the first file in my
> listfile but failed when it moves to the second file giving this error:Error: subscript out of bounds
>

Don't subscript then.
The only place where you're using the subscript is in

h=listfile[n]

The same can be made using the vector 'listfile' directly, for instance,
(dummy loop, just to see if it works.)

for(h in listfile){
print(h)
print(file.info(h)$size)
}

Hope this helps,

Rui Barradas

Jonsson

Re: Min , Max

Yes ,It worked. So how can I insert it in my code? Please

for(h in listfile){
+ print(h)
+ print(file.info(h)$size)
+ }
[1] "Wind_WFD_200101.nc.img"
[1] 66880640
[1] "Wind_WFD_200102.nc.img"
[1] 60408320
[1] "Wind_WFD_200103.nc.img"
[1] 66880640
[1] "Wind_WFD_200104.nc.img"
[1] 64723200
[1] "Wind_WFD_200105.nc.img"
[1] 66880640
[1] "Wind_WFD_200106.nc.img"
[1] 64723200
[1] "Wind_WFD_200107.nc.img"
[1] 66880640
[1] "Wind_WFD_200108.nc.img"
[1] 66880640
[1] "Wind_WFD_200109.nc.img"
[1] 64723200
[1] "Wind_WFD_200110.nc.img"
[1] 66880640
[1] "Wind_WFD_200111.nc.img"
[1] 64723200
[1] "Wind_WFD_200112.nc.img"
[1] 66880640