Rui, thanks so much for your help. Your explanation and example were
clear and concise. Thanks for taking the time and effort to help me.
-Kevin
On 5/12/23 16:06, Rui Barradas wrote:
> Às 14:24 de 12/05/2023, Kevin Zembower via R-help escreveu:
>> Hello, I'm trying to create a line graph with a legend, but have no
>> success controlling the legend. Since nothing I've tried seems to work,
>> I must be doing something systematically wrong. Can anyone point this
>> out to me?
>>
>> Here's my data:
>> > weights
>> # A tibble: 1,246 × 3
>> Date J K
>> <date> <dbl> <dbl>
>> 1 2000-02-13 133 188
>> 2 2000-02-20 134 185
>> 3 2000-02-27 135 187
>> 4 2000-03-05 135 185
>> 5 2000-03-12 NA 184
>> 6 2000-03-19 NA 184.
>> 7 2000-03-26 136 184.
>> 8 2000-04-02 134 185
>> 9 2000-04-09 133 186
>> 10 2000-04-16 NA 186
>> # ℹ 1,236 more rows
>> # ℹ Use `print(n = ...)` to see more rows
>> >
>>
>> Here's my attempts. You can see some of the things I've tried in the
>> commented out sections:
>> weights %>%
>> group_by(year(Date)) %>%
>> summarize(
>> m_K = mean(K, na.rm = TRUE),
>> m_J = mean(J, na.rm = TRUE),
>> ) %>%
>> ggplot(aes(x = `year(Date)`)) +
>> geom_point(aes(y = m_K, color = "red")) +
>> geom_smooth(aes(y = m_K, color = "red")) +
>> geom_point(aes(y = m_J, color = "blue")) +
>> geom_smooth(aes(y = m_J, color = "blue")) +
>> guides(size = "legend",
>> shape = "legend")
>> ## scale_shape_discrete(name="Person",
>> ## breaks=c("m_K", "m_J"),
>> ## labels=c("K", "J"))
>> ## theme(legend.title=element_blank())
>>
>> When this runs, the blue line for "K" is above the red line for "J", as
>> I expect, but in the legend, the red is shown first, and labeled "blue."
>>
>> I'd like to be able to create a legend where the first entry shows a
>> blue line and is labeled "K" and the second is red and labeled "J".
>>
>> On a different but related topic, I'd welcome any advice or suggestions
>> on my methodology in this example. Is this the correct way to summarize
>> with a mean? Do I need the two sets of geom_point and geom_line clauses
>> to create this graph, or is there a better way?
>>
>> Thanks for all your advice and guidance.
>>
>> -Kevin
>>
>>
>> ______________________________________________
>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
> Hello,
>
> This is mainly a data reshaping problem. Insteadof plotting two
> variables, J and K, if the data is in the long format you will map the
> column with these variables names to the color aesthetic and call each
> geom_* only once. Then, assign the colors you want.
>
> As for placing K above J, note that ggplot places them by alphabetical
> order unless you coerce to factor with the levels in the order you want.
>
> Also, if you want to compute aggregate statistics for several columns,
> use ?across. See the code below.
>
> Here is a complete example. I have augmented your data set in order to
> have more years to plot.
>
>
>
> # augment the data set
> weights <- " Date J K
> 1 2000-02-13 133 188
> 2 2000-02-20 134 185
> 3 2000-02-27 135 187
> 4 2000-03-05 135 185
> 5 2000-03-12 NA 184
> 6 2000-03-19 NA 184.
> 7 2000-03-26 136 184.
> 8 2000-04-02 134 185
> 9 2000-04-09 133 186
> 10 2000-04-16 NA 186"
> weights <- read.table(text = weights, header = TRUE)
> weights$Date <- as.Date(weights$Date)
> tmp <- weights
> tmp <- lapply(1:10, \(y) {
> tmp$Date <- years(y) + tmp$Date
> tmp$J <- tmp$J + sample(-10:10, nrow(weights), TRUE)
> tmp$K <- tmp$K + sample(-10:10, nrow(weights), TRUE)
> tmp
> })
> weights <- do.call(rbind, tmp)
>
> #---
>
> # plot code
> library(ggplot2)
> library(dplyr)
> library(tidyr)
> library(lubridate)
>
> weights %>%
> mutate(Year = year(Date)) %>%
> group_by(Year) %>%
> summarize(across(J:K, mean, na.rm = TRUE)) %>%
> # now reshape the data
> pivot_longer(-Year) %>%
> # uncomment the next line if you want K
> # to show up on top in the legend
> # mutate(name = factor(name, levels = c("K", "J"))) %>%
> ggplot(aes(Year, value, color = name)) +
> geom_smooth(
> formula = y ~ x,
> method = lm,
> se = FALSE
> ) +
> geom_point() +
> scale_color_manual(values = c(J = "red", K = "blue"))
>
>
>
> Hope this helps,
>
> Rui Barradas
>
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R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
