Tim, Richard, y'all are reading too much into this. I believe that TMAX is the high temperature of the day, and TMIN is the low. I'm trying to compute the average or median high and low temperatures for the data I have (2011 to present). I'm going on a trip to this area, and want to know how to pack.
Thanks for your interest. -Kevin On Thu, 2023-09-14 at 03:07 +1200, Richard O'Keefe wrote: > I am well aware of the physiological implications > of temperature, and that is *why* I view recorded > TMIN and TMAX at a single point with an extremely > jaundiced eye. TMAX at shoulder height has very > little relevance to an insect living in grass, for > example. And if TMAX is sustained for one second, > that has very different consequences from if TMAX > is sustained for five minutes. I can see the usefulness > of "proportion of day above Thi/below Tlo", but that > is quite different. > > OK, so my interest in weather data was mainly based > around water management: precipitation, evaporation, > herd and crop water needs, that kind of thing. And > the first thing you learn from that experience is > that ANY kind of single-point summary is seriously > misleading. > > Let's end this digression. > > > On Thu, 14 Sept 2023 at 02:18, Ebert,Timothy Aaron <teb...@ufl.edu> > wrote: > > 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%7C0d4da0f84a314d76ace60a62331 > > > e1b84 > > > %7C0%7C0%7C638302103358987487%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4 > > > wLjAw > > > MDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7 > > > C&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%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAw > > > MDAiL > > > CJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sda > > > ta=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.