在ggplot找不到的函数内创建的对象

I have a csv of time series data for a number of sites that I produce ggplots for, showing changes in means using the changepoint package. I have written a function that takes the csv, performs some calculations to get the means then loops through the sites producing a plot for each. My problem is that an object created in the for loop isn't found.I have a csv of time series data for a number o