Hi
Why you do not use twoord.plot from plotrix which should be designed for
such issue.
Something like
twoord.plot(lx = Year, ly = Li, rx = Year, ry= CR, data=yourdata)
Cheers
Petr
> -----Original Message-----
> From: R-help <r-help-bounces at r-project.org> On Behalf Of Ogbos
Okike
> Sent: Thursday, November 21, 2019 9:49 AM
> To: r-help <r-help at r-project.org>
> Subject: [R] Datetime in doubly y-axis plot
>
> Dear Members,
> I have some hourly data. Usin:
> dta$year <- with( dta, ifelse(year < 50, year + 2000, year + 1900))
> dta$datetime <- with( dta, as.POSIXct(ISOdatetime(year,
> month,day,hour,0,0)))
> I converted the hour to time format and stored in Year.
> The data consists of two different observations and I wish to plot
> same on one graph (two y-axis and common x-axis).
>
> Part of my script is of the form:
> library(plotrix)
>
plot(Year,Li,pch=16,axes=FALSE,xlab="",ylab="",type="l",col="black",ylim=c(> 1,22909))
> axis(2, ylim=c(1,22909),col="black",las=1)
> mtext("Lightning count/day", side=2, line=4)
> box()
> par(new=TRUE)
> plot(Year,CR, pch=15,
>
xlab="",ylab="",ylim=c(7302,9983),axes=FALSE,type="l",col="red")
> mtext("GCR count/day",side=4,col="red",line=3)
> axis(4, ylim=c(7302,9983),
col="red",col.axis="red",las=1)
> The two y-axis worked and looked fine.
>
> But I have difficulties with x-axis.
> I tried things like in an attempt to draw the x-axis.
> ## Draw the time axis
> #axis(1,pretty(range(Year),10))
> axis(side=1,at=c(as.datetime("2005-01-01 01:00:00
> GMT"),as.datetime("2007-01-01 01:00:00
GMT"),as.datetime("2009-01-01
> 01:00:00
GMT"),labels=c("2005","2007","2009"))
> #axis(side=1, at =Year)
> #axis(1,Year)
>
> But none worked.
>
> However, when I plotted the two graphs separately, the x-axis was
> correctly labelled from 2005 to 2010 (the time range of my data).
>
> Small portion of the data is:
> 04 12 31 10 8637 4992 0.310676228913214 49.7113438132607
> 04 12 31 11 8634 4183 0.275834035016405 25.4492290005748
> 04 12 31 12 8652 4160 0.484887198397259 24.7594531777172
> 04 12 31 13 8626 3411 0.182921517958247 2.2967535550946
> 04 12 31 15 8618 3904 0.09000900090009 17.0819483667808
> 04 12 31 16 8620 3428 0.113237130164629 2.80658785894585
> 04 12 31 17 8603 3041 -0.0842019685839552 -8.79964011696198
> 04 12 31 18 8579 2340 -0.362939519758427 -29.8228075875341
> 04 12 31 19 8588 3006 -0.258412938068 -9.8492989778322
> 04 12 31 20 8604 3280 -0.0725879039516855 -1.63196960987679
> 04 12 31 21 8568 3696 -0.490694230713394 10.8439757078949
> 04 12 31 22 8567 2307 -0.502308295345664 -30.8124859420688
> 04 12 31 23 8570 2726 -0.467466101448855 -18.2465698647939
> 05 01 01 00 8579 2879 -0.568878758318289 8.46755203918244
> 05 01 01 01 8581 1586 -0.545698639133843 -40.2467740416313
> 05 01 01 02 8562 1183 -0.765909771386082 -55.4299708015447
> 05 01 01 03 8602 1491 -0.302307387697159 -43.8259395309409
> 05 01 01 04 8576 1742 -0.603648937094958 -34.369407553923
> 05 01 01 05 8622 2001 -0.0705061958526974 -24.6114721672789
> 05 01 01 06 8613 2675 -0.174816732182705 0.781765093717623
> 05 01 01 07 8622 3293 -0.0705061958526974 24.0651784873316
> 05 01 01 08 8628 4333 -0.00096583829935895 63.2476217387209
> 05 01 01 09 8669 16 0.474226604981787 -99.3971931807479
> 05 01 01 10 8698 3671 0.810338333156256 38.3064895921635
> 05 01 01 11 8671 3856 0.497406724166233 45.2764434397664
> 05 01 01 12 8679 3411 0.590127200904018 28.5108787793162
> 05 01 01 13 8647 3428 0.219245293952879 29.1513610247716
> 05 01 01 14 8651 4596 0.265605532321772 73.156258830178
> 05 01 01 15 8638 3154 0.114934757622872 18.8282942450786
> 05 01 01 16 8635 2365 0.0801645788462025 -10.8976170292926
> 05 01 01 17 8628 2697 -0.00096583829935895 1.61062447018932
> 05 01 01 18 8653 3231 0.288785651506218 21.7293020627296
> 05 01 01 19 8657 3548 0.33514588987511 33.6724121691627
> 05 01 01 20 8650 2645 0.254015472729549 -0.348497692380145
> 05 01 01 21 8605 2153 -0.26753720892049 -18.8848073843835
> 05 01 01 22 8600 1759 -0.325487506881605 -33.7289253084676
> Where the first four columns are year, month, day and hour. The last
> four columns are the parameters of interest which I am trying to plot,
> taking two at a time.
> I will remain indebted for your assistance.
> Best Regards
> Ogbos
>
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