need some advice on x y plot

[nephish@xit.net]

Hey there,
i have tried about every graphing package for python i can get to work
on my system. gnuplot, pychart, biggles, gdchart, etc.. (cant get
matplot to work)
so far, they all are working ok. I need to make an x y chart for some
data that comes in from sensors at different times durring the day. i
need it to show the value in the y and the time in the x . no problem
so far. But what i cannot get to happen is to scale x (time of the
plot) with respect to time. in other words, i get a chart with the
times evenly spaced out along the x axis, with their respective values.
i need the chart to show gaps when there are gaps in the data. i need
it to be able to scale by time. if i have 3 values that come in within
a few minutes, i need them to be displayed close together, as compared
to another value that may come in, say, an hour later. Does this make
sence ?
one of you guys know a charting app that will do this ? or is there
some other way i could do it?

looking for suggestions,
sk

[Grant Edwards]

Re: need some advice on x y plot

On 2005-10-20, nephish@xit.net <nephish@xit.ne t> wrote:
[color=blue]
> [...] I need to make an x y chart for some data that comes in
> from sensors at different times durring the day. i need it to
> show the value in the y and the time in the x . no problem so
> far. But what i cannot get to happen is to scale x (time of
> the plot) with respect to time.[/color]

Gnuplot does that just fine. Just give it two columns of data, the
first being the x value (time) and the second being the y value.

All of the other plotting packages handle this as well.

--
Grant Edwards grante Yow! I hope I
at bought the right
visi.com relish... zzzzzzzzz...

[nephish@xit.net]

Re: need some advice on x y plot

how ?
i have tried to use unix timestamps, and i have also tried with
DateTime objects
do i need to use a scale that isn't linear (default in most) ?
how do i putt this off ?

thanks btw.
sk

[Larry Bates]

Re: need some advice on x y plot

I would try to live with time scale being fixed and insert
None (or whatever value is used by charting package) for
times where observations were not taken. This will mean that
you have to preprocess your data by determining a time step
step value that will fit your data. If you get 3 observations
each 10 minutes apart then one an hour later, you will need to
insert 5 empty observations in the list before the last
observation.

Example:

1:00 <value1>
1:10 <value2>
1:20 <value3>
2:20 <value4>

1:00 <value1>
1:10 <value2>
1:20 <value3>
1:30 <empty value>
1:40 <empty value>
1:50 <empty value>
2:00 <empty value>
2:10 <empty value>
2:20 <value4>

Maybe this will be of some help and I'm sure there are other ways.

-Larry

nephish@xit.net wrote:[color=blue]
> Hey there,
> i have tried about every graphing package for python i can get to work
> on my system. gnuplot, pychart, biggles, gdchart, etc.. (cant get
> matplot to work)
> so far, they all are working ok. I need to make an x y chart for some
> data that comes in from sensors at different times durring the day. i
> need it to show the value in the y and the time in the x . no problem
> so far. But what i cannot get to happen is to scale x (time of the
> plot) with respect to time. in other words, i get a chart with the
> times evenly spaced out along the x axis, with their respective values.
> i need the chart to show gaps when there are gaps in the data. i need
> it to be able to scale by time. if i have 3 values that come in within
> a few minutes, i need them to be displayed close together, as compared
> to another value that may come in, say, an hour later. Does this make
> sence ?
> one of you guys know a charting app that will do this ? or is there
> some other way i could do it?
>
> looking for suggestions,
> sk
>[/color]

[nephish@xit.net]

Re: need some advice on x y plot

i have thought about doing this, just a little different. i was going
to list the value pairs.
take the start time and end time and plot 100 empty plots between them.
add the value pairs, sort by time, and then draw it. The only thing is
it get kinda complicated when the times change a lot. they could span
an hour, a month, anything in between.

i like your idea, i will check various packages for how to plot 'none'

thanks
sk.

[Grant Edwards]

Re: need some advice on x y plot

On 2005-10-20, nephish@xit.net <nephish@xit.ne t> wrote:
[color=blue]
> i have tried to use unix timestamps,[/color]

That has always worked for me. What happened?
[color=blue]
> and i have also tried with DateTime objects[/color]

Never tried that.
[color=blue]
> do i need to use a scale that isn't linear (default in most) ?[/color]

No.
[color=blue]
> how do i putt this off ?[/color]

Huh?

Gnuplot by default does exactly what you seem to want if you
just pass it x,y values.

--
Grant Edwards grante Yow! I always liked FLAG
at DAY!!
visi.com

[Grant Edwards]

Re: need some advice on x y plot

On 2005-10-20, Larry Bates <larry.bates@we bsafe.com> wrote:
[color=blue]
> I would try to live with time scale being fixed[/color]

I don't understand what you mean by "the time scale being
fixed". It's not. If you just pass the time,value pairs to
gnuplot, it does exactly what it should.
[color=blue]
> and insert
> None (or whatever value is used by charting package) for
> times where observations were not taken. This will mean that
> you have to preprocess your data by determining a time step
> step value that will fit your data. If you get 3 observations
> each 10 minutes apart then one an hour later, you will need to
> insert 5 empty observations in the list before the last
> observation.
>
> Example:
>
> 1:00 <value1>
> 1:10 <value2>
> 1:20 <value3>
> 2:20 <value4>
>
> 1:00 <value1>
> 1:10 <value2>
> 1:20 <value3>
> 1:30 <empty value>
> 1:40 <empty value>
> 1:50 <empty value>
> 2:00 <empty value>
> 2:10 <empty value>
> 2:20 <value4>[/color]

That's completely unnecessary. Just pass a set of time,value
pairs and they'll get plotted as desired.

--
Grant Edwards grante Yow! As a FAD follower,
at my BEVERAGE choices are
visi.com rich and fulfilling!

[Grant Edwards]

Re: need some advice on x y plot

On 2005-10-20, Grant Edwards <grante@visi.co m> wrote:
[color=blue][color=green]
>> and insert None (or whatever value is used by charting
>> package) for times where observations were not taken. This
>> will mean that you have to preprocess your data by determining
>> a time step step value that will fit your data. If you get 3
>> observations each 10 minutes apart then one an hour later, you
>> will need to insert 5 empty observations in the list before
>> the last observation.[/color][/color]
[...][color=blue]
>
> That's completely unnecessary. Just pass a set of time,value
> pairs and they'll get plotted as desired.[/color]

For example, here's how gnuplot plots the data

2 12
3 10
4 9
101 8
102 6
103 9



20 ++----------+-----------+-----------+----------+-----------+----------++
+ + + + + "foo.dat" A +
| |
| |
| |
15 ++ ++
| |
| |
|A |
| |
10 ++A ++
| A A |
| A |
| |
| A |
5 ++ ++
| |
| |
| |
+ + + + + + +
0 ++----------+-----------+-----------+----------+-----------+----------++
0 20 40 60 80 100 120


Isn't that what you're asking for?

--
Grant Edwards grante Yow! ... I have read the
at INSTRUCTIONS...
visi.com

[Kent Johnson]

Re: need some advice on x y plot

nephish@xit.net wrote:[color=blue]
> how ?
> i have tried to use unix timestamps, and i have also tried with
> DateTime objects
> do i need to use a scale that isn't linear (default in most) ?
> how do i putt this off ?[/color]

Here is some code that works for me. It plots multiple datasets against time. The input data looks like this:
2005-04-04 16:00:00 141.154.195.129 - W3SVC1 SP6018ASP2 208.254.37.191 443 GET /rkadqsr/newskills/newskills.cfm selectedTab=1 200 0 53440 599 1594 HTTP/1.1 adqsr.skillport .com Mozilla/4.0+(compatible ;+MSIE+6.0;+Win dows+NT+5.1) CookiesEnabled= 1;+ASPSESSIONID ACTSSRAT=MCNLNL GADPOFGFKAHJHLD DKG;+CFID=78503 0;+CFTOKEN=2720 3160 https://adqsr.skillport.com/rkadqsr/login/login.cfm
2005-04-04 16:00:00 208.254.38.216 - W3SVC1 SP6018ASP2 208.254.37.191 443 POST /_rkadqsrBackend _od_cgi/aiccisapi.dll - 200 0 372 274 4547 HTTP/1.0 adqsr.skillport .com aiccisapi - -
2005-04-04 16:00:00 208.254.38.240 - W3SVC1 SP6018ASP2 208.254.37.191 443 POST /_rkadqsrBackend _od_cgi/aiccisapi.dll - 200 0 372 3019 250 HTTP/1.0 adqsr.skillport .com aiccisapi - -

import datetime, time
import Gnuplot

dataPath = 'ex05040416.log '

datasets = {}
startTime = None

f = open(dataPath)

for line in f:
try:
dat, tim, c_ip, cs_username, s_sitename, s_computername, s_ip, s_port, \
cs_method, cs_uri_stem, cs_uri_query, sc_status, sc_win32_status , sc_bytes, \
cs_bytes, time_taken, cs_version, cs_host, cs_User_Agent, cs_Cookie, cs_Referer = line.split()
except ValueError:
print "Can't parse", line
continue

tim = time.mktime(tim e.strptime(dat+ ' '+tim, "%Y-%m-%d %H:%M:%S"))
delay = int(time_taken)

if startTime is None:
startTime = tim

tim -= startTime

# print tim, delay
datasets.setdef ault(sc_status, []).append([tim, delay])

g = Gnuplot.Gnuplot (debug=1)

plotter = g.plot
for key, values in datasets.items( ):
plotter(values)
plotter = g.replot

raw_input('Plea se press return to continue...\n')

[nephish@xit.net]

Re: need some advice on x y plot

ok, yeah, thats exactly what i am looking for. i will give it a go.
thanks a whole lot.

putt this off is a typo, pull this off is what i was meaning to type.

this is cool.

[nephish@xit.net]

Re: need some advice on x y plot

ok, i tried something similar to what you posted.
a little simpler though.
i am running a query on a database and making a list of time, value
pairs
kinda like this
plot_points = ([time, value], [time, value], [time, value])
gnuplot complains that it needs a float for one of the values.
i can plot just the value, and it shows up ( no x value found)

how should i proceed?

[Kent Johnson]

Re: need some advice on x y plot

nephish@xit.net wrote:[color=blue]
> i am running a query on a database and making a list of time, value
> pairs
> kinda like this
> plot_points = ([time, value], [time, value], [time, value])
> gnuplot complains that it needs a float for one of the values.
> i can plot just the value, and it shows up ( no x value found)
>
> how should i proceed?[/color]

Convert one of the values to a float? What are your time and value numbers?

Kent

[nephish@xit.net]

Re: need some advice on x y plot

the time is DateTime.DateTi me object from a mySQLdb query.
the value is a number anywhere between 0 and 15.
the datetime is formatted like 2005-10-20 08:40:34

i could strip it and make a timestamp out of it. but reading the
number of seconds since january of 1970 doesn't make a neat chart.

any suggestions?

oh, and can you output from Gnuplot to a png or jpeg or something like
that.
the Gnuplot documentation says that it can make a bitmap png but i dont
know how to do that with the python wrapper. the docs for this are a
little cryptic.
still a newbie here. if you know a good tutorial on this, i would
really appreciate the link.

thanks for your time, and brain

[William Park]

Re: need some advice on x y plot

nephish@xit.net wrote:[color=blue]
> the time is DateTime.DateTi me object from a mySQLdb query.
> the value is a number anywhere between 0 and 15.
> the datetime is formatted like 2005-10-20 08:40:34
>
> i could strip it and make a timestamp out of it. but reading the
> number of seconds since january of 1970 doesn't make a neat chart.
>
> any suggestions?[/color]

Python is capable of integer arithmetic, eg.[color=blue][color=green][color=darkred]
>>> 2000 - 500[/color][/color][/color]
1500

--
William Park <opengeometry@y ahoo.ca>, Toronto, Canada
ThinFlash: Linux thin-client on USB key (flash) drive

http://home.eol.ca/~parkw/thinflash.html

BashDiff: Super Bash shell

http://freshmeat.net/projects/bashdiff/

[Grant Edwards]

Re: need some advice on x y plot

On 2005-10-21, nephish@xit.net <nephish@xit.ne t> wrote:
[color=blue]
> the time is DateTime.DateTi me object from a mySQLdb query. the
> value is a number anywhere between 0 and 15. the datetime is
> formatted like 2005-10-20 08:40:34
>
> i could strip it and make a timestamp out of it. but reading
> the number of seconds since january of 1970 doesn't make a
> neat chart.[/color]

Pass the data values as floating point numbers (I typically use
seconds since the test run started). If you the x tics to be
something else, then change them. It's pretty simple to label
the x-axis using normal date/time notation.
[color=blue]
> any suggestions?
>
> oh, and can you output from Gnuplot to a png or jpeg or
> something like that.[/color]

Is that a question? If so, the answer is yes.
[color=blue]
> the Gnuplot documentation says that it can make a bitmap png
> but i dont know how to do that with the python wrapper. the
> docs for this are a little cryptic. still a newbie here. if
> you know a good tutorial on this, i would really appreciate
> the link.[/color]

Once you start doing "odd" stuff (e.g. custom labels for the x-axis,
output other than X11 or postscript), it's usually simplest to
just send normal gnuplot commands.

------------------------------8<------------------------------
import Gnuplot,time,sy s,math

def pause():
sys.stdout.writ e("Press enter to continue: ")
sys.stdin.readl ine()

def fgrid(start,sto p,count):
for i in xrange(count):
yield start + ((stop-start)*i)/count

start = time.time()

xdata = [x for x in fgrid(0,600.0,1 0)] # two minutes worth
ydata = [math.sin(x/100.0) for x in xdata]

data = Gnuplot.Data(xd ata,ydata,with= 'linespoints')

gp = Gnuplot.Gnuplot ()
gp.title('Data starting at %s' % time.ctime(star t+xdata[0]))

# x axis will use default tics (seconds since start of run)
gp.plot(data)
pause()

# now let's change x tics to time of day in HH:MM:SS with
# ticmarks at 120 second intervals

ti = 120.0
startTic = int((start+xdat a[0])//ti * ti)
endTic = int((start+xdat a[-1])//ti * ti)
ti = int(ti)

ticx = range(startTic, endTic+ti,ti)
tics = [(x, time.strftime(' %H:%M:%S',time. localtime(x))) for x in ticx]
ticstrings = ['"%s" %f' % (t[1],t[0]-start) for t in tics]

gp('set xtics (%s)' % ','.join(ticstr ings))
gp.plot(data)
pause()

outfile = 'foo.png'
gp('set term png')
gp('set out "%s"' % outfile)
gp.plot(data)
------------------------------8<------------------------------

--
Grant Edwards grante Yow! ... The waitress's
at UNIFORM sheds TARTAR SAUCE
visi.com like an 8" by 10" GLOSSY...