match_row {expss}

Match finds value in rows or columns/index returns value by index from rows or columns

Description

match finds value in rows or columns. index returns value by index from row or column. One can use functions as criteria for match. In this case position of first value on which function equals to TRUE will be returned. For convenience there are special predefined functions - see criteria. If value is not found then NA will be returned.

Usage

match_row(criterion, ...)

match_col(criterion, ...)

index_row(index, ...)

index_col(index, ...)

value_row_if(criterion, ...)

value_col_if(criterion, ...)

Arguments

criterion

Vector of values to be matched, or function.

...

data. Vectors, matrixes, data.frames, lists. Shorter arguments will be recycled.

index

vector of positions in rows/columns from which values should be returned.

Value

vector with length equals to number of rows for *_row and equals to number of columns for *_col.

Examples

# toy data
v1 = 1:3
v2 = 2:4
v3 = 7:5

# postions of 1,3,5 in rows
match_row(c(1, 3, 5), v1, v2, v3) # 1:3
# postions of 1,3,5 in columns
match_col(1, v1, v2, v3) # c(v1 = 1, v2 = NA, v3 = NA)

# postion of first value greater than 2
ix = match_row(gt(2), v1, v2, v3) 
ix # c(3,2,1)
# return values by result of previous 'match_row' 
index_row(ix, v1, v2, v3) # c(7,3,3)

# the same actions with data.frame
dfs = data.frame(v1, v2, v3)

# postions of 1,3,5 in rows
match_row(c(1, 3, 5), dfs) # 1:3
# postions of 1,3,5 in columns
match_col(1, dfs) # c(v1 = 1, v2 = NA, v3 = NA)

# postion of first value greater than 2
ix = match_row(gt(2), dfs) 
ix # c(3,2,1)
# return values by result of previous 'match_row' 
index_row(ix, dfs) # c(7,3,3)