var() keeps returning NA or NaN R

Question

I am trying to compute the variance for a variable in my data frame, var(df$var) keeps returning NA or NaN however. the variable is the ratio between two original variables; FOODperINC = FOODexp / TOTALINC

var() of FOODexp and TOTALINC do return numbers.

I have searched and tried the following:

remove NA's from original variables and FOODperINC.

add 1 to TOTALING, to avoid dividing over 0

var(as.numeric()) / var(as.vector())

I do not quite understand why I can;t compute the variance. What am I doing wrong?

My code for reference:

df4 = df3[!is.na(df3$FOODTOT.x),]
df4 = df4[!is.na(df4$FINCAFTM.x),]


df4$FINCAFTM.x = df4$FINCAFTM.x +1
df4$INCperFOOD = df4$FOODTOT.x / df4$FINCAFTM.x

df3$SEAperINC.x = df3$SEAFOOD.x / df3$FINCAFTM.x
df3$FOODperINC.x = df3$FOODTOT.x / df3$FINCAFTM.x

var.test(df3$FOODperINC.x, df3$SEAperINC.x)

var(df4$FOODperINC.x)


var(df3$SEAperINC.x, na.rm=T)
var(as.numeric(df4$FOODperINC.x), na.rm=T)
which(is.null(df4$FOODperINC.x))

cov(df5$SEAperINC.x, df3$FOODperINC.x)
View(df4$FOODperINC.x)

Answer 1

brainfart;

df4$INCperFOOD != df4$FOODperINC

Thank you Ossan!

"INCperFOOD", "FOODperINC", "FOODperINC.x",), row.names = c(NA, 
5L), class = "data.frame")