Re: precision of y-axis values in plot
- To: mathgroup at smc.vnet.net
- Subject: [mg123783] Re: precision of y-axis values in plot
- From: Mike H <mike.honeychurch at gmail.com>
- Date: Mon, 19 Dec 2011 07:17:18 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- References: <jccgik$min$1@smc.vnet.net>
Okay here is what is happening.
Firstly your limits variable is capturing the y axis range.
If we change the tick function to this:
tickFunction[min_, max_] := (Print[{min, max}];
Table[{i, NumberForm[i, {3, 4}]}, {i, min, max, 1/7}])
Plot[Sin[x], {x, 0, 1}, Ticks -> {tickFunction, tickFunction}]
We get both ranges printed.
{-0.0208333,1.02083}
{-0.0175306,0.859002}
Now you might ask why, when you are plotting from 0 to 1 why we are getting
{-0.0208333,1.02083} parsed to the tick function. The answer is because it
turns that the plot range used in the tick function includes the plot range
padding. When you set
Plot[Sin[x], {x, 0, 1}, Ticks -> {tickFunction, tickFunction},
PlotRangePadding -> 0]
{0.,1.}
{0.,0.841471}
and the ticks are exactly where you expect them. I didn't notice this when
I wrote the answer yesterday. As for the documentation, I haven't looked at
tick funcitons in years but I am sure I remember it being there in the old
(V4, V5)documentation.
Mike
On Mon, Dec 19, 2011 at 5:59 AM, DrMajorBob <btreat1 at austin.rr.com> wrote:
> The behavior of Ticks -> func is not explained in Help for Ticks -- and no
> examples are given -- so I suppose any guess is as good as another. It's
> pretty clear that Table[{i, NumberForm[i, {3, 4}]}, {i, min, max, 1/7}]
> should yield tick marks separated by about
>
> 1/7.
>
> 0.142857
>
> The question is what "min" and "max" arguments are used.
>
> When I run this code:
>
> tickFunction[min_, max_] := Table[{i, NumberForm[i, {3, 4}]}, {i, min,
> max, 1/7}]
>
> Plot[Sin[x], {x, 0, 1}, Ticks -> tickFunction]
>
> The ticks I see are {0.1220, 0.2650, 0.4081, 0.5510, .6930, .8360,
> 0.9790}, which are spaced just about right:
>
> differences =
> Subtract @@@
> Partition[
> ticks = {0.1220, 0.2650, 0.4081, 0.5510, .6930, .8360, 0.9790}, 2,
> 1]
> -7 Rationalize@Mean@%
>
> {-0.143, -0.1431, -0.1429, -0.142, -0.143, -0.143}
>
> 5999/6000
>
> xmin = 0.1220 should be the first tick mark, and xmax could be 1.12186:
>
> Through[{First, Last}@ticks] + {0, 1}/7
> (tickFunction @@ %)[[All, 1]]
>
> {0.122, 1.12186}
>
> {0.122, 0.264857, 0.407714, 0.550571, 0.693429, 0.836286, 0.979143}
>
> but those are not the plotted tick marks. (Close, but no cigar.)
>
> If we modify tickFunction to get the arguments directly, a very different
> result arises:
>
> tickFunction[min_, max_] := (limits = {min, max};
> Table[{i, NumberForm[i, {3, 4}]}, {i, min, max, 1/7}])
> Plot[Sin[x], {x, 0, 1}, Ticks -> tickFunction];
> limits
> (tickFunction @@ limits)[[All, 1]]
>
> {-0.0175306, 0.859002}
>
> {-0.0175306, 0.125326, 0.268184, 0.411041, 0.553898, 0.696755, \
> 0.839612}
>
> Those are really, REALLY not the tick marks on the plot.
>
> Don't you just love the documentation?
>
> Bobby
>
> On Sun, 18 Dec 2011 03:36:44 -0600, Armand Tamzarian <
> mike.honeychurch at gmail.com> wrote:
>
> On Dec 17, 6:44 pm, Nathan <nhroll... at gmail.com> wrote:
>>
>>> On Dec 16, 4:04 am, Armand Tamzarian <mike.honeychu... at gmail.com>
>>> wrote:
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> > On Dec 15, 9:01 pm, Nathan <nhroll... at gmail.com> wrote:
>>>
>>> > > Hi,
>>>
>>> > > I'm relatively new to Mathematica. I'm having a problem with the
>>> > > precision of the y-axis values of some of my plots. All of the data
>>> > > labels show up as "2422.3", which isn't very informative since
>>> they're
>>> > > all the same. I need the plot to show two more decimal point values
>>> > > (ex: "2422.305"). I've looked high and low and can't find any way to
>>> > > do this. Any ideals? Thanks!
>>>
>>> > > Nathan.
>>>
>>> > What you need to do is make a tick function and wrap NumberForm around
>>> > your labels and set the number of decimal points that you want. If you
>>> > do a search on here for tick functions and NumberForm you should find
>>> > many examples.
>>>
>>> > Mike
>>>
>>> Mike,
>>>
>>> Thank you for your help. Forgive my ignorance, but what should I put
>>> in the NumberForm function? Here's the plot command I'm using:
>>>
>>> plot2T := Plot[LT2[T, \[Lambda]], {T, min2, max2}, Frame -> True,
>>> FrameLabel -> {{"Task Execution Time (s)", ""}, {"Optimal CSCP
>>> Checkpoint Interval (s)", ""}}, FrameStyle -> {{Black, White},
>>> {Black, White}}, Axes -> {False, False}]
>>>
>>> Based on what you said, I assume I should add something like the
>>> following to the Plot function:
>>> Tick -> NumberForm[ N[?], 8]
>>>
>>> However, I'm not sure what should replace the ?. Will you please
>>> indulge a newbie with a specific example? Thanks!
>>>
>>
>>
>> tickFunction[min_, max_] := Table[{i, NumberForm[i, {3, 4}]}, {i, min,
>> max, 1/7}]
>>
>> Plot[Sin[x], {x, 0, 1}, Ticks -> tickFunction]
>>
>> You will need to read the documentation on Ticks and NumberForm to get
>> this to do exactly what you want.
>>
>> Mike
>>
>>
>
> --
> DrMajorBob at yahoo.com
>
- Follow-Ups:
- Re: precision of y-axis values in plot
- From: DrMajorBob <btreat1@austin.rr.com>
- Re: precision of y-axis values in plot