# R – + signs appearing in console in R

r

I´m quite new at programming, and I started with R. I wanted to make a script which takes as input a matrix with the columns: time, x, y (coordenates) and then divide the time spent in each quadrant of a circular area. I have a roughly done script, but for any reason I don´t understand, when I execute the for loop in the editor, it appears all the letters red in the console with a "+" at the beginning of each line, which doesn´t let me open any other object any more when I call it.

``````set.seed(20)
x = matrix(rnorm(10,3,4),10,1)
y = matrix (rnorm(10,3,4),10,1)
time = matrix (1:10,10,1)
a = cbind (time,x,y)
colnames(a) = c("time","x","y")

upperright =  a[,2] > 0 && a[,3] > 0
upperleft =   a[,2] < 0 && a[,3] > 0
lowerright =  a[,2] > 0 && a[,3] < 0
lowerleft =   a[,2] < 0 && a[,3] < 0

calculation <- function () {
for (i in c(1:nrow(a))){
}}
output = lapply (a, calculation)
``````

#### Best Solution

The `+` symbols are only a way to show that the current statement is conitnuation of the previous lines's statement. That's perfectly OK. There are a couple of other problems with your program which are stopping it from producing your intended result. If I have in fact, understood what you are trying to do, I have added a possible solution at the end. First, let me suggest the edits and the reason for them:

1. `&` should have been used instead of `&&`. `&` is the vectorized operator. So, `upperright = a[,2] > 0 & a[,3] > 0` instead of `upperright = a[,2] > 0 && a[,3] > 0`.
2. You are passing a value to the function so its definition should include the parameter `calculation <- function (a)` instead of `calculation <- function ()`.
3. upperright, upperleft, ... are vectors and you should check individual elements instead of the whole vector `if (upperright[i])` instead of `if (upperright)`.
4. Problem with `sum((a[i,1]-a[i-1,1]))` at i==1, i-1 equals 0. If you are only counting, incrementing the count by 1 should be sufficient.
5. The objects upperrightquadrant, upperleftquadrant, ... are in your function environment only. So, no need for `<<-`.
6. Finally, as you have already written the `for` loop to iterate over your matrix rowwise, no need for lapply or other similar looping functions.

Only a suggestion: Use `<-` operator for assignments instead of `=`.

Now, the corrected program:

``````set.seed(20)
x = matrix(rnorm(10,3,4),10,1)
y = matrix (rnorm(10,3,4),10,1)
time = matrix (1:10,10,1)
a = cbind (time,x,y)

colnames(a) = c("time","x","y")

upperright =  a[,2] > 0 & a[,3] > 0
upperleft =   a[,2] < 0 & a[,3] > 0
lowerright =  a[,2] > 0 & a[,3] < 0
lowerleft =   a[,2] < 0 & a[,3] < 0

calculation <- function (a) {
for (i in c(1:nrow(a))){
}

}
output = calculation(a)

print(a)        # input
print(output)   # output
``````

## EDIT

This is the edit for what you requested (Case where time instances are not contiguous). Just replace the `for` loop with this one:

``````  for (i in c(1:nrow(a))){
if(i>1){