Coding and addition of explanatory variables
On Tue, 9 Jun 2020, Julian Burgos wrote:
Very hard to say without a reproducible example. But perhaps "DVI1" is not in your "Trainingset" dataframe?
Thanks, here is a code example: library(randomForest) data(airquality) set.seed(131) ozone.rf1 <- randomForest(Ozone ~ Solar.R + Wind + Temp + Month + Day, data=airquality, proximity=TRUE, importance=TRUE, na.action=na.omit) print(ozone.rf1) set.seed(131) ozone.rf2 <- randomForest(Ozone ~ Solar.R + Wind + Temp + Month + day, data=airquality, proximity=TRUE, importance=TRUE, na.action=na.omit) # Error in eval(predvars, data, env) : object 'day' not found Concise code examples always help to tease out problems, Roger
________________________________
From: R-sig-Geo <r-sig-geo-bounces at r-project.org> on behalf of Enoch Gyamfi Ampadu <egampadu at gmail.com>
Sent: Tuesday, June 9, 2020 14:06
To: Help R-Sig_Geo <r-sig-geo at r-project.org>
Subject: [R-sig-Geo] Coding and addition of explanatory variables
Dear List,
Please I am doing a biomass analysis with a satellite image. The
explanatory variables include the satellite bands and vegetation indices. I
am using Random forest regression. I have added bands of the satellite
image to the model and it worked. However, when I tried to add the
vegetation indices (bands) I get error messages. I have put the codes I am
using below;
Model <- randomForest(class~ B1 + B2 + B3 + B4 + B5 + B6 + B7 + B8 + B9 +
B10 + B11 + B12 + DVI1, data = Trainingset, proximity=TRUE,
importance=TRUE).
The "DVI1" is the vegetation index variable band I tried to add to the
model.
Below is the error message I received.
"Error in eval(predvars, data, env) : object 'DVI1' not found"
I will be glad if I could get some assistance on how to resolve it.
Best regards,
Enoch
--
*Enoch Gyamfi - Ampadu*
*Geography & Environmental Sciences*
*College of Agriculture, Engineering & Science*
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Roger Bivand Department of Economics, Norwegian School of Economics, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; e-mail: Roger.Bivand at nhh.no https://orcid.org/0000-0003-2392-6140 https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en