I need to create a StatisticalBarChart that not just has one value for standard deviation but a positive and negative standard deviation.
So that the deviation is not symmetrical around the mean value.
This is how it's supposed to look:
Any ideas? Thanks in advance!
alt text http://dl.dropbox.com/u/1144075/Bildschirmfoto%202010-07-25%20um%2014.05.11.JPG
You'll have to extend BarRenderer to override drawItem() and extend AbstractDataset to provide the extra data, as suggested in the PLSNPAIRS classes, AsymmetricStatisticalBarRenderer and AsymmetricStatisticalCategoryDataset.
Related
I have a nonlinear equation that uses an initial y'(a) and outputs a value y(b) such that y(b)=f(y'(a)), where f(x) is some function. The idea is that I'd like to be able to maximize y(b).
Typically, if I had a value for y(b), I could use the shooting or secant method. However I don't have that value. I was thinking I could use a loop to find the max value, but that is very inefficient. Anything better I could use?
*Edit: Also I do not have an explicit expression for f(x).
Thanks,
Mike
can any one explain why(how) the xtype: numberfield value is going to auto correct(change) if am providing more than a 16 digits value.
For Example:
22222222222222222 is changed to 22222222222222224
222222222222222222 is changed to 222222222222222200
2222222222222222222 is changed to 2222222222222222300
22222222222222222222 is changed to 22222222222222220000
222222222222222222222 is changed to 222222222222222230000
2222222222222222222222 is changed to 2.2222222222222222e+21
22222222222222222222222 is changed to 2.2222222222222223e+22
Which results in my page after rendering as shown below when get the value through in my component jsp page
NumberFieldTestValue:<%= properties.get("numberfieldname","") %>
Resulting as below
NumberFieldTestValue: 2.2222222222222223e+22
The problem
This behavior is caused by the fact that the dialog behavior is implemented in JavaScript. The numbers you're having problems with cannot be represented in it.
The language conforms to the ECMASCRIPT 5.1 specification.
To quote the Number type description
all the positive and negative integers whose magnitude is no greater
than 2^53 are representable in the Number type
The base 2 logarithm of 2222222222222222222222 is about 70, which means the number exceeds the maximum value. Hence your problems.
All in all, if you check your examples in a plain JS console in a browser, the same behavior will be displayed so this is not really a CQ problem.
Solution 1 - use a different type
To avoid this, you could potentially use xtype="textfield" and validate it against a regular expression to see if it consists of numbers only. Then you'd have to make sure to use a type capable of holding such numbers at the backend (like BigInteger).
The field could look like this:
<numberOfSandGrains
jcr:primaryType="cq:Widget"
fieldLabel="Number of grains of sand at the beach"
name="./grainsCount"
regex="/\d+/"
regexText="Please enter a numeric value."
xtype="textfield"/>
Solution 2 - change scale
Another option is to change the logic behind the configuration and use some different units if applicable. For instance, if the value 2222222222222222222222 is a number of grams (weight of an object/substance), it makes perfect sense to read it in metric tons instead (at least in many cases). The author could probably do without entering such humongous numbers.
You'll need to be extra-careful if you go this way.
I have found this link: http://www.jfree.org/forum/viewtopic.php?f=3&t=6314
Its back in 2007 where they agree that infinity should be supported in JFreeChart.
Anyone know if it is supported or not? I need to be able to support this. Or be able to draw a line on the X axis that doesn't have an end.
There is no general support in JFreeChart for the concept of infinity, other than that offered by Double.
The Unicode character ∞, named INFINITY (U+221E), may be used to compose a String literal. You can also render the glyph, as shown here, or obtain an outline using GlyphVector, mentioned here, or via TextLayout, illustrated here.
For additional guidance, please edit your question to include an sscce that exhibits your intended usage, e.g. title, legend, axis, annotation, label, shape, etc.
I am working on an application that displays surface winds. Wind speed and direction will be displayed using "wind barb" symbols, as described here: Plotted Winds
My question: Are there any standards for the angles and lengths of the "flags" in relation to the wind-barb "pole"?
Eyeballing the diagrams I've seen, I think that an angle of 60 degrees and a flag length about a third as long as the pole length would look fine, but if there are any officially defined standards for these symbols, I'd like to follow them.
Note: This app will not be used for navigation, so it is not very important that it look exactly like an official chart. I just don't want it to be ugly, or to look obviously wrong to a knowledgeable user.
I found this program that draws weather maps. I think you can get the source code.
http://www.ncarg.ucar.edu//supplements/wmap/index.html#HEADING1-139
am trying to calculate mean and variance using 3X3 window over image(hXw) in opencv...here is my code...is there any accuracy issues with this??or is there any other efficient method to do it in one pass.?
int pi,a,b;
for(i=1;i<h-1;i++)
{
for(j=1;j<w-1;j++)
{ int sq=0,sum=0;
double mean=0;
double var=0;
for(a=-1;a<=1;a++)
{
for(b=-1;b<=1;b++)
{
pi=data[(i+a)*step+(j+b)];
sq=pi*pi;
sum=sum+sq;
mean=mean+pi;
}
}
mean=mean/9;
double soa=mean*mean;//square of average
double aos=sum/9;//mean of squares
double var=aos-soa;//variance
}
}
With respect to computational efficiency I would recommend doing this in the Fourier domain instead of the time (image) domain using convolutions. Remember, a convolution is a simple multiplication in the Fourier domain. Just like in time series where the spectral density function is the variance decomposed as a function of frequency, one can extend this into two dimensions for an image. Should be much better than nested for-loops.
I don't have the code on me at the moment. but this technique has been used in algorithms like "fast template matching" for object detection or image registration.
That is a pretty well-researched topic, see e.g. this Wikipedia article on variance calculations.
One of the issues that sometimes gets mentioned is accumulated numerical errors; you need to decide if that may be an issue. If the values you compute over are similar in range that it may be less of an issue.
You should be fine even with floats over such a small number of pixels. Typically you need doubles if you're doing this kind of thing over an entire image.
You should better use image integrals for quick local mean and standard deviation calculation!
All you need in that case is to correctly calculate the boundaries of the mask window at each position of the image. It will be much more faster.
If you will need a sample code, please ask for that.