I had the same question.
However, I can partly answer the off-topic question. Min and max can be
important as lower and upper development thresholds. Below the min no growth or
development occur because reaction rates are too slow to enable such. Above
max, temperatures are too hot. Protein function is impaired, and systems stop
functioning. There is a considerable range between where systems shut down (but
recover) and tissue death.
In a simple form the growth and physiological stage of plants, insects, and
many others, can be modeled as a function of temperature. These are often
called growing degree day models (or some version of that). This is number of
thermal units needed for the organism to develop to the next stage (e.g. instar
for an insect, or fruit/flower formation for a plant). However, better accuracy
is obtained if the model includes both min and max thresholds.
All I have done is provide an example where min and max could have a real world
use. I use max(temp) over some interval and then update an accumulated thermal
units variable based on the outcome. That detail is not evident in the original
request.
Tim
-----Original Message-----
From: R-help <r-help-boun...@r-project.org> On Behalf Of Richard O'Keefe
Sent: Wednesday, September 13, 2023 9:58 AM
To: Kevin Zembower <ke...@zembower.org>
Cc: r-help@r-project.org
Subject: Re: [R] Help with plotting and date-times for climate data
[External Email]
Off-topic, but what is a "mean temperature max"
and what good would it do you to know you if you did?
I've been looking at a lot of weather station data and for no question I've
ever had (except "would the newspapers get excited about this") was "max" (or
min) the answer. Considering the way that temperature can change by several
degrees in a few minutes, or a few metres -- I meant horizontally when I wrote
that, but as you know your head and feet don't experience the same temperature,
again by more than one degree -- I am at something of a loss to ascribe much
practical significance to TMAX. Are you sure this is the analysis you want to
do? Is this the most informative data you can get?
On Wed, 13 Sept 2023 at 08:51, Kevin Zembower via R-help <
r-help@r-project.org> wrote:
> Hello,
>
> I'm trying to calculate the mean temperature max from a file of
> climate date, and plot it over a range of days in the year. I've
> downloaded the data, and cleaned it up the way I think it should be.
> However, when I plot it, the geom_smooth line doesn't show up. I think
> that's because my x axis is characters or factors. Here's what I have so far:
> ========================================
> library(tidyverse)
>
> data <- read_csv("Ely_MN_Weather.csv")
>
> start_day = yday(as_date("2023-09-22")) end_day =
> yday(as_date("2023-10-15"))
>
> d <- as_tibble(data) %>%
> select(DATE,TMAX,TMIN) %>%
> mutate(DATE = as_date(DATE),
> yday = yday(DATE),
> md = sprintf("%02d-%02d", month(DATE), mday(DATE))
> ) %>%
> filter(yday >= start_day & yday <= end_day) %>%
> mutate(md = as.factor(md))
>
> d_sum <- d %>%
> group_by(md) %>%
> summarize(tmax_mean = mean(TMAX, na.rm=TRUE))
>
> ## Here's the filtered data:
> dput(d_sum)
>
> > structure(list(md = structure(1:25, levels = c("09-21", "09-22",
> "09-23", "09-24", "09-25", "09-26", "09-27", "09-28", "09-29",
> "09-30", "10-01", "10-02", "10-03", "10-04", "10-05", "10-06",
> "10-07", "10-08", "10-09", "10-10", "10-11", "10-12", "10-13",
> "10-14", "10-15"), class = "factor"), tmax_mean = c(65,
> 62.2222222222222, 61.3, 63.8888888888889, 64.3, 60.1111111111111,
> 62.3, 60.5, 61.9, 61.2, 63.6666666666667, 59.5, 59.5555555555556,
> 61.5555555555556, 59.4444444444444, 58.7777777777778,
> 55.8888888888889, 58.125, 58, 55.6666666666667, 57, 55.4444444444444,
> 49.7777777777778, 48.75, 43.6666666666667)), class = c("tbl_df",
> "tbl", "data.frame"
> ), row.names = c(NA, -25L))
> >
> ggplot(data = d_sum, aes(x = md)) +
> geom_point(aes(y = tmax_mean, color = "blue")) +
> geom_smooth(aes(y = tmax_mean, color = "blue"))
> =====================================
> My questions are:
> 1. Why isn't my geom_smooth plotting? How can I fix it?
> 2. I don't think I'm handling the month and day combination correctly.
> Is there a way to encode month and day (but not year) as a date?
> 3. (Minor point) Why does my graph of tmax_mean come out red when I
> specify "blue"?
>
> Thanks for any advice or guidance you can offer. I really appreciate
> the expertise of this group.
>
> -Kevin
>
> ______________________________________________
> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat/
> .ethz.ch%2Fmailman%2Flistinfo%2Fr-help&data=05%7C01%7Ctebert%40ufl.edu
> %7C41f002949dac426196de08dbb4619001%7C0d4da0f84a314d76ace60a62331e1b84
> %7C0%7C0%7C638302103358987487%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAw
> MDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sda
> ta=dfC3W%2F%2BBsZI0EaAx%2FocRgw81PSJH8sVZHPFB4rMyiaM%3D&reserved=0
> PLEASE do read the posting guide
> http://www.r/
> -project.org%2Fposting-guide.html&data=05%7C01%7Ctebert%40ufl.edu%7C41
> f002949dac426196de08dbb4619001%7C0d4da0f84a314d76ace60a62331e1b84%7C0%
> 7C0%7C638302103358987487%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiL
> CJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=zR
> IyH2os0w%2Bi1M26YCGqRFZyXNN6KnS2ddNrEZ9BvVo%3D&reserved=0
> and provide commented, minimal, self-contained, reproducible code.
>
[[alternative HTML version deleted]]
______________________________________________
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.
______________________________________________
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.
