[R] time series x axis labels

[Felipe Carrillo]

I hope this is the appropriate list for this type of question
Consider the dataset below:I have a column DOC with values from 3 to 101and those are the values that I want to show on my x axis, howeverI only get 3, 3.1, 3.2 and so on. I tried to change those values with xlim(3, 101) but I getthe following error:Error in unit(x, default.units) : 'x' and 'units' must have length > 0
question: Which argument is needed in the ts() call to make the x axis showbreaks every 7 days starting with 3?
wt <- structure(list(DOC = c(3, 10, 17, 24, 31, 38, 45, 52, 59, 66, 73, 80, 87, 94, 101), AvgWeight = c(1, 1.66666666666667, 2.06666666666667, 2.275, 3.83333333333333, 6.2, 7.4, 8.5, 10.25, 11.1, 13.625, 15.2, 16.375, 17.8, 21.5), PondName = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = "Pond01", class = "factor"),     SampleDate = structure(c(1182585600, 1183190400, 1183795200,     1184400000, 1185004800, 1185609600, 1186214400, 1186819200,     1187424000, 1188028800, 1188633600, 1189238400, 1189843200,     1190448000, 1191052800), class = c("POSIXct", "POSIXt"))), .Names = c("DOC", "AvgWeight", "PondName", "SampleDate"), row.names = c(NA, 15L), class = "data.frame")  
wt$SampleDate <- as.Date(wt$SampleDate)  wt
library(forecast)library(ggplot2)pond <- ts(wt$AvgWeight,start=3,frequency=52)pond d.arima <- auto.arima(pond)d.forecast <- forecast(d.arima, level = c(95), h = 3)d.forecast

autoplot(d.forecast) + xlim(7, 101)Error in unit(x, default.units) : 'x' and 'units' must have length > 0

Take a look at the attached plot

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