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...model <- aov(Rotationdata_R$`GY(Mg/ha)`~Rep+code*as.factor(Nitrogen),data=Rotationdata_R) Ahmed Attia, Ph.D. Agronomist & Soil Scientist On Mon, Dec 25, 2017 at 7:38 PM, David Winsemius <dwinsemius at comcast.net> wrote: > >> On Dec 25, 2017, at 10:21 AM, Ahmed Attia <ahmedatia80 at gmail.com> wrote: >> >> LSD.test > > ?LSD.test > No documentation for ?LSD.test? in specified packages and libraries: > you could try ???LSD.test? > > -- > David Winsemius > Alameda, CA, USA > > 'Any technology distinguishable from magic is insuff...

> On Dec 25, 2017, at 2:09 PM, Ahmed Attia <ahmedatia80 at gmail.com> wrote: > > The model should be class aov or lm and my model class is aovlist. > tried tidy from broom library but did not work. To make it class aov, > I had to remove the error term; > > model <- aov(Rotationdata_R$`GY(Mg/ha)`~Rep+code*as.factor(Nitrogen),da...

...have to do with what your objective actually is, > like what you are modeling and what you are doing with the > predictions. But my sample code might be enough to get you headed in > the right direction regardless. > > Sarah > > On Fri, Jun 30, 2017 at 9:27 AM, Ahmed Attia <ahmedatia80 at gmail.com> wrote: >> Hi folks, >> >> I have 25 stand height observations over 7 years period and daily >> leafbiomass data during this period. I want to use the 25 plant height >> observations as inputs and predict the daily stand height during the 7 >> yea...

---------- Forwarded message ---------- From: <r-help-owner@r-project.org> Date: Mon, Jan 14, 2013 at 12:31 AM Subject: Help with nonlinear regression To: ahmedatia80@gmail.com The message's content type was not explicitly allowed ---------- Forwarded message ---------- From: Ahmed Attia <ahmedatia80@gmail.com> To: r-help@r-project.org Cc: Date: Mon, 14 Jan 2013 00:31:41 -0800 Subject: Help with nonlinear regression Hi- I have a question ab...

Dear All, I'm a beginner user in R and I would like to make a quadratic and plateau model in R. Can you help please with an example? Thanks so much -- Ahmed M. Attia Assistant Lecturer El-Khattara farm Station Agronomy Dept., Zgazig Univ., Egypt Visiting Scientist Haskell Agricultural laboratory Agronomy and Horticultural Dept., Univ. of Nebraska-Lincoln ahmedatia at zu.edu.eg

...your variable. This time, you are overwriting the entirety of Stand_Height with the timeseries of height. Perhaps you should spend some time with one of the good introductory R resources out there, and think a bit more about your procedure. Sarah On Fri, Jun 30, 2017 at 11:23 AM, Ahmed Attia <ahmedatia80 at gmail.com> wrote: > Sorry for the confusion, here is the edited question. > > The data= Stand_Height (attached) is recorded from 12/1/2009 to > 12/31/2015 (25 observations) and the other dataset (leafbiom) is > recorded from 10/7/2009 to 12/29/2016 (daily observations). > &g...

Hi R users, I need your help to write a code in r that does the following calculation from three different datasets; ac = 1/sum (NPP from date 1 to date 2, dataset=1) * (biomass at date 2 -biomass at date 1, dataset = 2) + (littfall at date 2, dataset=3). all the dates are in yr-month-day format. Which library or function Should I use to tell R do these calculations of these variables at

LSD-test produces error for this code; code <- as.factor(Rotationdata_R$`Rot/code`) #factor in the main Nitrogen <- as.factor(Rotationdata_R$Nitrogen) #factor in the sub Rep <- as.factor(Rotationdata_R$REP) #blocks Year <- as.factor(Rotationdata_R$YEAR) #years model <- aov(Rotationdata_R$`GY(Mg/ha)`~Rep+code*as.factor(Nitrogen)+Error(Rep/Year/code),data=Rotationdata_R)

> On Dec 25, 2017, at 10:21 AM, Ahmed Attia <ahmedatia80 at gmail.com> wrote: > > LSD.test ?LSD.test No documentation for ?LSD.test? in specified packages and libraries: you could try ???LSD.test? -- David Winsemius Alameda, CA, USA 'Any technology distinguishable from magic is insufficiently advanced.' -Gehm's Corollary to Cl...

...s.Date() to it makes no sense to me, since the elapsed numbers of days are not dates. > > -- > Don MacQueen > > Lawrence Livermore National Laboratory > 7000 East Ave., L-627 > Livermore, CA 94550 > 925-423-1062 > > > On 7/5/17, 11:23 AM, "Ahmed Attia" <ahmedatia80 at gmail.com> wrote: > > How can I convert date to continuous variable staring from 1. I tried > as.numeric but R starts counting from default January 1, 1970 while my data > start Oct 7, 2009. > > I need to do this conversion to plot the date on two x-axes (1 a...

...u may have to convert character strings to dates to do the above - see a function like "as.Date". Obviously I do not know the actual names of your datasets and I am assuming that the variable names you have given are the actual ones. Jim On Thu, Jun 22, 2017 at 4:19 AM, Ahmed Attia <ahmedatia80 at gmail.com> wrote: > Hi R users, > > I need your help to write a code in r that does the following > calculation from three different datasets; > > ac = 1/sum (NPP from date 1 to date 2, dataset=1) * (biomass at date 2 > -biomass at date 1, dataset = 2) + (littfall at date...

...problem; the rest of my questions have to do with what your objective actually is, like what you are modeling and what you are doing with the predictions. But my sample code might be enough to get you headed in the right direction regardless. Sarah On Fri, Jun 30, 2017 at 9:27 AM, Ahmed Attia <ahmedatia80 at gmail.com> wrote: > Hi folks, > > I have 25 stand height observations over 7 years period and daily > leafbiomass data during this period. I want to use the 25 plant height > observations as inputs and predict the daily stand height during the 7 > years. > > > SH=ma...

Hi folks, I have 25 stand height observations over 7 years period and daily leafbiomass data during this period. I want to use the 25 plant height observations as inputs and predict the daily stand height during the 7 years. SH=matrix(data=NA , nrow = 2641, ncol = 1) for (i in 1:2641) { SH<- predict(lm(height~Date, data=Stand_Height)); dl=leafbiom$Date[i-1]; de=leafbiom$Date[i];

...o open the file and explore it's contents - you should get a clear picture of it's contents from that. Something like this (untested)... library(ncdf4) x <- nc_open(file.nc) x nc_close(x) While print lots of info about the file. Ben > On Mar 28, 2018, at 10:37 AM, Ahmed Attia <ahmedatia80 at gmail.com> wrote: > > Hi > > I have a netCDF file of volumetric soil water content at four > different soil layers and want to convert each soil layer in the > netCDF file to a GeoTIFF layer. This code converts the netCDF file to > one GeoTIFF layer, i.e. unclear which...

Hi I have a netCDF file of volumetric soil water content at four different soil layers and want to convert each soil layer in the netCDF file to a GeoTIFF layer. This code converts the netCDF file to one GeoTIFF layer, i.e. unclear which soil depth. file.nc <- "C:/Soil_Weather_data/Agro/VMC21/VMC21.nc" file.tiff <- "C:/Soil_Weather_data/Agro /VMC21/VMC21" importnetcdf

I have probably an old question. I have R.3.0.1 installed in 64 bit windows 7. The odbcConnectExcel in RODBC library does not work. Tried odbcConnectExcel2007 still does not work. Any ideas. Thanks Melissa<-sqlFetch(odbcConnectExcel2007("F:\\Cotton2012\\validation.xlsx"),sqtable = "Sheet3", + na.strings = "NA", as.is = TRUE) Error in

How can I convert date to continuous variable staring from 1. I tried as.numeric but R starts counting from default January 1, 1970 while my data start Oct 7, 2009. I need to do this conversion to plot the date on two x-axes (1 and 3). Ex; Date LAI 10/7/2009 0 10/8/2009 0.004173 10/9/2009 0.009997 10/10/2009 0.009998 10/11/2009 0.009999 10/12/2009 0.009999 10/13/2009 0.009999 10/14/2009 0.009999

Dear R users, Can I fit nls.lm to a non-continuous date data. looked at previous examples but still not able to fit the model to my data. There are 25 rows of observations as below; df <- data.frame(Date=as.Date(rownames(df),'%m/%d/%Y'),Y=df$height) df$days <- as.numeric(df$Date - df[1,]$Date) head(df) Date Y days 1 2009-12-01 0.2631250 0 2 2010-01-08 0.4436012

Hello R users, The code below is for loop in R that I want to do to following calculation at each time i and i-1 in 2:75 dataset (Litterfall_Ahmed97). ac = ((LeafBiog at date i -LeafBiog at date i-1, dataset = leafbiom97) + (littperiod at date i, dataset= Litterfall_Ahmed97))/(sum (GPP from date i-1 to date i, dataset=GPP_Ahmed13)/2) . #code for loop GPP_Ahmed13$Date <-

Please help getting the R squared value in asymptotic regression model I use the code below model1<-nls(GN1~SSasymp (nrate,a,b,c), data = data.1 ) and R produced the modell coefficients without the R squared value? -- Ahmed M. Attia Research Assistant Dept. Of Soil&Crop Sciences Texas A&M University ahmed <ahmedatia@zu.edu.eg>.attia@ag.tamu.edu Cell phone: