Delete row in dataframe R - r

I used
milsa <- edit(data.frame())
To open the R Data Editor and now I can type the data of my table.
My problem is: my table has 36 rows, but for some reason I have 39 rows appearing in the program (the 3 additional rows are all filled with NA).
When I try to use:
length(civil)
I'm getting 39 instead of 36. How can I solve this? I am trying to use fix(milsa) but it can't delete the additional rows.
PS: Civil is a variable of milsa.

Subset with the index:
You can reassign the data.frame to itself with only the rows you want to keep.
milsa <- milsa[1:36,]
Here is a LINK to a quick tutorial for your reference

To delete specific rows
milsa <- milsa[-c(row_num1, row_num2, row_num3), ]
To delete rows containing one or more NA's
milsa <- na.omit(milsa)

Related

Create a new row to assign M/F to a column based on heading, referencing second table?

I am new to R (and coding in general) and am really stuck on how to approach this problem.
I have a very large data set; columns are sample ID# (~7000 samples) and rows are gene expression (~20,000 genes). Column headings are BIOPSY1-A, BIOPSY1-B, BIOPSY1-C, ..., BIOPSY200-Z. Each number (1-200) is a different patient, and each sample for that patient is a different letter (-A, -Z).
I would like to do some comparisons between samples that came from men and women. Gender is not included in this gene expression table. I have a separate file with patient numbers (BIOPSY1-200) and their gender M/F.
I would like to code something that will look at the column ID (ex: BIOPSY7-A), recognize that it includes "BIOPSY7" (but not == BIOPSY7 because there is BIOPSY7-A through BIOPSY7-Z), find "BIOPSY7" in the reference file, extrapolate M/F, and create a new row with M/F designation.
Honestly, I am so overwhelmed with coding this that I tried to open the file in Excel to manually input M/F, for the 7000 columns as it would probably be faster. However, the file is so large that Excel crashes when it opens.
Any input or resources that would put me on the right path would be extremely appreciated!!
I don't quite know how your data looks like, so I made mine based on your definitions. I'm sure you can modify this answer based on your needs and your dataset structure:
library(data.table)
genderfile <-data.frame("ID"=c("BIOPSY1", "BIOPSY2", "BIOPSY3", "BIOPSY4", "BIOPSY5"),"Gender"=c("F","M","M","F","M"))
#you can just read in your gender file to r with the line below
#genderfile <- read.csv("~/gender file.csv")
View(genderfile)
df<-matrix(rnorm(45, mean=10, sd=5),nrow=3)
colnames(df)<-c("BIOPSY1-A", "BIOPSY1-B", "BIOPSY1-C", "BIOPSY2-A", "BIOPSY2-B", "BIOPSY2-C","BIOPSY3-A", "BIOPSY3-B", "BIOPSY3-C","BIOPSY4-A", "BIOPSY4-B", "BIOPSY4-C","BIOPSY5-A", "BIOPSY5-B", "BIOPSY5-C")
df<-cbind(Gene=seq(1:3),df)
df<-as.data.frame(df)
#you can just read in your main df to r with the line below, fread prevents dashes to turn to period in r, you need data.table package installed and checked in
#df<-fread("~/first file.csv")
View(df)
Note that the following line of code removes the dash and letter from the column names of df (I removed the first column by df[,-c(1)] because it is the Gene id):
substr(x=names(df[,-c(1)]),start=1,stop=nchar(names(df[,-c(1)]))-2)
#[1] "BIOPSY1" "BIOPSY1" "BIOPSY1" "BIOPSY2" "BIOPSY2" "BIOPSY2" "BIOPSY3" "BIOPSY3" "BIOPSY3" "BIOPSY4" "BIOPSY4"
#[12] "BIOPSY4" "BIOPSY5" "BIOPSY5" "BIOPSY5"
Now, we are ready to match the columns of df with the ID in genderfile to get the Gender column:
Gender<-genderfile[, "Gender"][match(substr(x=names(df[,-c(1)]),start=1,stop=nchar(names(df[,-c(1)]))-2), genderfile[,"ID"])]
Gender
#[1] F F F M M M M M M F F F M M M
Last step is to add the Gender defined above as a row to the df:
df_withGender<-rbind(c("Gender", as.character(Gender)), df)
View(df_withGender)

RMYSQL Writetable error

I have the following R dataframe
Sl NO Name Marks
1 A 15
2 B 20
3 C 25
I have a mysql table as follows. (Score.table)
No CandidateName Score
1 AA 1
2 BB 2
3 CC 3
I have written my dataframe to Score.table using this code
username='username'
password='userpass'
dbname='cdb'
hostname='***.***.***.***'
cdbconnection = dbConnect(MySQL(), user=username, password=userpass,
dbname=dbname, host=hostname)
Next we write the dataframe to the table as follows
score.table<-'score.table'
dbWriteTable(cdbconn, score.table, dataframe, append =F, overwrite=T).
The code runs and I get TRUE as the output.
However, when I check the SQL table, the new values haven't overwritten the existing values.
I request someone to help me. The code works. I have reinstalled the RMySQL package again and rerun and the results are the same.
That updates are not happening indicates that the RMySQL package cannot successfully map any of the rows from your data frame to already existing records in the table. So this would imply that your call to dbWriteTable has a problem. Two potential problems I see are that you did not assign values for field.types or row.names. Consider making the following call:
score.table <- 'score.table'
dbWriteTable(cdbconn, score.table, dataframe,
field.types=list(`Sl NO`="int", Name="varchar(55)", Marks="int"),
row.names=FALSE)
If you omit field.types, then the package will try to infer what the types are. I am not expert with this package, so I don't know how robust this inference is, but most likely you would want to specify explicit types for complex update queries.
The bigger problem might actually be not specifying a value for row.names. It can default to TRUE, in which case the package will actually send an extra column during the update. This can cause problems, for example if your target table has three columns, and the data frame also has three columns, then you are trying to update with four columns.

Using order in R dataframes fails after column names have been changed. how can I recover this?

Setup dataframe
mta<-c("ldall","nold","ldall","nold","ldall","nold","ldall","nold")
mtb<-c(491, 28581,241,5882,365,7398,512,10887)
df1<-data.frame(mta,mtb)
I can order my dataframe in the normal way. This works fine.
df1[order(mtb),]
But if I change the names of the columns
names(df1)<-c("mta1","mtb1")
df1[order(mtb1),]
This gives the error
Error in order(mtb1) : object 'mtb1' not found.
If I use the old column name in the instruction it works, although the output shows the new column name.
df1[order(mtb),]
If I change the name back to the original, the command appears to work normally. Can anyone explain? Is order using a hidden version of the column name?
This should work. Let me know if this helps.
mta<-c("ldall","nold","ldall","nold","ldall","nold","ldall","nold")
mtb<-c(491, 28581,241,5882,365,7398,512,10887)
df1<-data.frame(mta,mtb)
# Change column names
colnames(df1) <- c("mta1","mtb1")
# Sort column mtb1 from the data frame
df1[order(df1$mtb1), ]
mta1 mtb1
3 ldall 241
5 ldall 365
1 ldall 491
7 ldall 512
4 nold 5882
6 nold 7398
8 nold 10887
2 nold 28581

Checking for number of items in a string in R

I have a very large csv file (1.4 million rows). It is supposed to have 22 fields and 21 commas in each row. It was created by taking quarterly text files and compiling them into one large text file so that I could import into SQL. In the past, one field was not in the file. I don't have the time to go row by row and check for this.
In R, is there a way to verify that each row has 22 fields or 21 commas? Below is a small sample data set. The possibly missing field is the 0 in the 10th slot.
32,01,01,01,01,01,000000,123,456,0,132,345,456,456,789,235,256,88,4,1,2,1
32,01,01,01,01,01,000001,123,456,0,132,345,456,456,789,235,256,88,5,1,2,1
you can use the base R function count.fields to do this:
count.fields(tmp, sep=",")
[1] 22 22
The input for this function is the name of a file or a connection. Below, I supplied a textConnection. For large files, you would probably want to feed this into table:
table(count.fields(tmp, sep=","))
Note that this can also be used to count the number of rows in a file using length, similar to the output of wc -l in the *nix OSs.
data
tmp <- textConnection(
"32,01,01,01,01,01,000000,123,456,0,132,345,456,456,789,235,256,88,4,1,2,1
32,01,01,01,01,01,000001,123,456,0,132,345,456,456,789,235,256,88,5,1,2,1"
)
Assuming df is your dataframe
apply(df, 1, length)
This will give you the length of each row.

R storing different columns in different vectors to compute conditional probabilities

I am completely new to R. I tried reading the reference and a couple of good introductions, but I am still quite confused.
I am hoping to do the following:
I have produced a .txt file that looks like the following:
area,energy
1.41155882174e-05,1.0914586287e-11
1.46893363946e-05,5.25011714434e-11
1.39244046855e-05,1.57904991488e-10
1.64155121046e-05,9.0815757601e-12
1.85202830392e-05,8.3207522281e-11
1.5256036289e-05,4.24756620609e-10
1.82107587343e-05,0.0
I have the following command to read the file in R:
tbl <- read.csv("foo.txt",header=TRUE).
producing:
> tbl
area energy
1 1.411559e-05 1.091459e-11
2 1.468934e-05 5.250117e-11
3 1.392440e-05 1.579050e-10
4 1.641551e-05 9.081576e-12
5 1.852028e-05 8.320752e-11
6 1.525604e-05 4.247566e-10
7 1.821076e-05 0.000000e+00
Now I want to store each column in two different vectors, respectively area and energy.
I tried:
area <- c(tbl$first)
energy <- c(tbl$second)
but it does not seem to work.
I need to different vectors (which must include only the numerical data of each column) in order to do so:
> prob(energy, given = area), i.e. the conditional probability P(energy|area).
And then plot it. Can you help me please?
As #Ananda Mahto alluded to, the problem is in the way you are referring to columns.
To 'get' a column of a data frame in R, you have several options:
DataFrameName$ColumnName
DataFrameName[,ColumnNumber]
DataFrameName[["ColumnName"]]
So to get area, you would do:
tbl$area #or
tbl[,1] #or
tbl[["area"]]
With the first option generally being preferred (from what I've seen).
Incidentally, for your 'end goal', you don't need to do any of this:
with(tbl, prob(energy, given = area))
does the trick.

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