Am trying to merge about 15 .csv tables - tried a test run but came up with 0 rows (no data for each variable/column head)> CAHSEE.EA.feb.2009<-read.csv("2009 CAHSEE EA feb 2009.csv", header=TRUE) > CAHSEE.IM.MATH.2009<-read.csv("2009 CAHSEE Impact Math.csv", header=TRUE) > testmerge<-merge(CAHSEE.EA.feb.2009,CAHSEE.IM.MATH.2009) > testmerge[1] Grade LocalStudentID MathPassed MathScaleScore SchoolCode [6] LastName FirstName ELAPassed ELAScaleScore MathTestDate <0 rows> (or 0-length row.names) I know several variables are shared in both sheets. Please advise. [[alternative HTML version deleted]]
On 02/09/2011 09:21 PM, Benjamin Caldwell wrote:> Am trying to merge about 15 .csv tables - tried a test run but came up with > 0 rows (no data for each variable/column head) > >> CAHSEE.EA.feb.2009<-read.csv("2009 CAHSEE EA feb 2009.csv", header=TRUE) >> CAHSEE.IM.MATH.2009<-read.csv("2009 CAHSEE Impact Math.csv", header=TRUE) >> testmerge<-merge(CAHSEE.EA.feb.2009,CAHSEE.IM.MATH.2009) >> testmerge > [1] Grade LocalStudentID MathPassed MathScaleScore SchoolCode > > [6] LastName FirstName ELAPassed ELAScaleScore > MathTestDate > <0 rows> (or 0-length row.names) > > I know several variables are shared in both sheets. Please advise.Please provide a reproducible example, otherwise we have no idea what your objects that are giving you trouble look like. You can use the ?dput function to facilitate this. In general, I end up with your situation when I have data that differ between the common names in the two data.frames. You might try the "by" argument in merge... Best. --Erik
You want advice? 1. Write sentences that contain a subject and where appropriate, an object as well. This makes your email just that bit more polite. This list is not a paid service. 2. The "sheets" may have variables in common, but do they have the same name in both, and the same class, and some values in common? You do not give us very much to go on. -----Original Message----- From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of Benjamin Caldwell Sent: Thursday, 10 February 2011 1:22 PM To: r-help Subject: [R] merge multiple .csv files Am trying to merge about 15 .csv tables - tried a test run but came up with 0 rows (no data for each variable/column head)> CAHSEE.EA.feb.2009<-read.csv("2009 CAHSEE EA feb 2009.csv", header=TRUE) > CAHSEE.IM.MATH.2009<-read.csv("2009 CAHSEE Impact Math.csv", header=TRUE) > testmerge<-merge(CAHSEE.EA.feb.2009,CAHSEE.IM.MATH.2009) > testmerge[1] Grade LocalStudentID MathPassed MathScaleScore SchoolCode [6] LastName FirstName ELAPassed ELAScaleScore MathTestDate <0 rows> (or 0-length row.names) I know several variables are shared in both sheets. Please advise. [[alternative HTML version deleted]] ______________________________________________ R-help at r-project.org 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.