plot level, velocity, acceleration with one x axis

On 5/30/23 8:48 AM, Eric Berger wrote:

I am a bit confused as to what you are trying to achieve - and  even
if I could guess it is not clear what the interpretation would be.

head(DAX)

1628.75 1613.63 1606.51 1621.04 1618.16 1610.61

Including the leading NA's, what would be the 6 leading terms of the 3
series that you want to plot,
and what would be the Y labels that you want to appear at those levels
(assuming that there was a
Y label for each of them - just to understand the units you are talking about)

DAX <- EuStockMarkets[, 'DAX']
DAX. <- cbind(DAX, diff(log(DAX)), diff(diff(log(DAX))))
colnames(DAX.) <- c("DAX", 'vel (%)', 'accel (%)')
head(DAX.)


          DAX exhibits growth that is roughly exponential, so I want to plot it
on a log scale:


plot(DAX.[, 1], log='y', ylab='DAX')
plot(DAX.[, 2], ylab='vel (%)')
plot(DAX.[, 3], ylab='accel (%)')


          This is what I want as three panels of a single plot.


          I think I could get it by modifying the code for plot.ts so it
accepted ylab as a vector, etc., as I previously mentioned.


          What do you think?
          Thanks,
          Spencer Graves

On Tue, May 30, 2023 at 4:06?PM Spencer Graves
<spencer.graves at effectivedefense.org> wrote:

On 5/30/23 6:16 AM, Eric Berger wrote:

My code assumes that DAX is a ts object, as in your original post.

On Tue, May 30, 2023 at 2:06?PM Eric Berger <ericjberger at gmail.com> wrote:

Untested but why not

a <- cbind(log(DAX), exp(diff(log(DAX))), exp(diff(diff(log(DAX)))))
colnames(a) <- c("logDAX", "vel", "accel")
plot(a)

           Progress, but we're not there yet.


a <- cbind(DAX, exp(diff(log(DAX))), exp(diff(diff(log(DAX)))))
colnames(a) <- c("logDAX", "vel", "accel")
plot(a)
plot(a, axes=FALSE, log='y')
axis(1)
axis(2)


           How do I get each y axis labeled in its original units?  I can use
pretty to get where I want tick marks, but I don't know where to place
them "at" in calling axis(2, at= ___)?


(axlb1 <- pretty(range(a[, 1])))
(axlb2 <- pretty(range(log(a[, 2]), na.rm=TRUE)))
(axlb3 <- pretty(range(log(a[, 3]), na.rm=TRUE)))


           This suggests I write my own modification of plot.ts that accepts log
as a character vector of length = ncol of the ts being plotted and
returns invisibly a list with the default "at" and "label" arguments
required to produce the default labeling.  Then a user who wants a log
scale for some but not all variables can get that easily and can further
modify any of those scales further if they don't like the default.


           ???
           Thanks very much.
           Spencer Graves

On Tue, May 30, 2023 at 1:46?PM Spencer Graves
<spencer.graves at effectivedefense.org> wrote:

On 5/29/23 2:37 AM, Eric Berger wrote:

How about this:

a <- cbind(AirPassengers, diff(log(AirPassengers)),
diff(diff(log(AirPassengers))))
colnames(a)[2:3] <- c("percent increase", "acceleration")
plot(a, xlab="year", main="AirPassengers")

            My real problem is more difficult:  I'm analyzing CO2 data from Our
World in Data (https://ourworldindata.org/co2-emissions), and I need to
plot the CO2 data on a log scale but velocity and acceleration on linear
scales.  The following is comparable:


str(DAX <- EuStockMarkets[, 'DAX'])
str(DAX. <- cbind(DAX, diff(log(DAX)),
                     diff(diff(log(DAX)))))
colnames(DAX.)[2:3] <- c('vel', 'accel')
plot(DAX.)


            I want the first of the three panels to plot on the log scale, but
the other two on linear scales.  The obvious attempt does not work:


plot(DAX., log=c('y', '', ''))
#Error in length(log) && log != "" :
#  'length = 3' in coercion to 'logical(1)'


            Trying to construct my own axes isn't easy, either:


str(logDAX <- cbind(log(DAX), diff(log(DAX)),
                     diff(diff(log(DAX)))))
colnames(logDAX) <- c('logDAX', 'vel', 'accel')
plot(logDAX, axes=FALSE)
axis(1)
axis(2)


            I'm thinking of creating my own copy of "plot.ts", and changing it so
it accepts the "log" argument as a vector of length equal to ncol of the
ts object to be plotted AND returning an object that would allow a user
to call "axis" ncol times.


            Suggestions?


            Thanks,
            Spencer Graves

HTH,
Eric


On Mon, May 29, 2023 at 7:57?AM Spencer Graves
<spencer.graves at effectivedefense.org> wrote:

Hello, All:


             I want to plot level, velocity, and acceleration in three panels with
only one x axis.  The code below does this using "layout".  However, I
want the three plot areas to be of equal size, and this won't do that:
If I stretch the plot vertically, the relative sizes of the three panels
changes.  There's probably a way to do this with ggplot2, but I have yet
to find it.


             Suggestions?
             Thanks,
             Spencer Graves


str(AirTime <- as.numeric(time(AirPassengers)))
str(AP <- as.numeric(AirPassengers))

def.par <- par(no.readonly = TRUE) # save default, for resetting...
(mat3x1 <- matrix(1:3, 3))
plot3x1 <- layout(mat3x1, heights=c(1.4, 1, 1.5))
layout.show(plot3x1)

par(mar=c(0, 4.1, 4.1, 2.1))
plot(AirTime, AP, log='y', type='l', axes=FALSE,
         main='AirPassengers', ylab='AirPassengers')
box(col='grey')
axis(2, las=1)

par(mar=c(0, 4.1, 0, 2.1))
vAP <- diff(log(AP))
plot(tail(AirTime, -1), vAP, type='l',
         ylab='percent increase', axes=FALSE)
box(col='grey')
axis(2, las=1)

par(mar=c(5.1, 4.1, 0, 2.1))
plot(tail(AirTime, -2), diff(vAP), type='l',
         ylab='acceleration', xlab='year',
         las=1)
box(col='grey')

par(def.par)