Cchart Daily Lesson--happy started playing against tenth lesson see around corners, Cchart built-in function introduction of data processing

The Cchart built-in data processing function is not turned on by default. To turn on the data processing feature, click the menu "drawing status--special features--Allow data processing", where the Menu "curve data--data name" will have a "data processing" menu.

As you can see, stupid built-in four data processing functions, linear transformations, calculus, data smoothing, data fitting.

The A10.1 linear transform "linear Transform" menu provides three functions, namely, offset, zoom, and transform. These three functions are very simple, just look at the pop-up dialog box to understand it all.

Visible, for the offset function, set the x, y direction of the offset value, for the zoom function, you need to set the Zoom Center and zoom factor, for the transformation function, you need to set the affine transformation of 6 coefficients. In fact, the affine transform function completely overrides the offset and zoom functions.

The Reserveold data in the dialog box indicates whether the original curve is preserved after the transformation processing.

Since these features are very simple, they do not show the effect.

The A10.2 calculus "Calculus" menu provides two functions, namely differential and integral. The following is a dialog box with two functions for differentiation and integration.

For the differential function, the differential method is divided into three kinds of back-to-forward differential, forward differential and bidirectional differential, and for integral function, the integral method is divided into left integral, right integral and center integral three kinds.

Let's draw a sine curve.

Select the state after differential.

Select the status after the integration.

A10.3 Data Smoothing "Data Smoothing" menu provides two functions, namely median filter and mean filter. The dialog box that pops up is as follows.

Set the number of points to filter here.

The effect is not shown here either.

A10.4 Data Fitting

The Data Fit menu provides a variety of functions, including polynomial fitting, exponential function fitting, logarithmic function fitting, single-peak Gaussian function fitting, and multi-peak Gaussian function fitting. These are stupid and stupid usually use more, for other functions, if necessary can also be added.

The following is a silly demonstration of a complex point of multi-peak Gaussian fitting.

We know that the Gaussian distribution expression is Y=a*exp ( -0.5* ((x-b)/C) ^2), where B is the central location of the distribution, C represents the width of the peak, and a represents the height of the peak. Multi-peak words, is in many places have a high eggishorn.

We draw three peaks superimposed, three peaks (A, B, c) respectively (3, 2, 0.3), (2, 6,0.5), (5, 10, 0.4), and we also add a background of 0.6.

So get the curve.

We click on the multi-peak Gaussian fitting menu and pop up the following dialog box.

Since we have three peaks here, Gaussianpeaks should choose 3.

In the peak no drop-down list box, select the first few peaks, and then set the initial value of the peak in the ak,bk,ck below. The key to the initial value is the position of the peak BK do not go too far, the height of the peak AK and width CK does not matter.

The position of the three peaks previously known is in 2,6,10. We set three Peaks BK initial values to be 1.5,7,10.5 respectively. A result dialog box pops up after fitting.

You can see that the fitting results are exactly the same as the initial values we set. Let's take a look at the fitting curve and the original curve, and the two curves are completely coincident.

Let's add a random noise to the original curve.

Fitting according to the above method, fitting the result.

The resulting values are very close to the initial value we set, indicating a successful fit.

The visible fitting curve describes the envelope of the original curve perfectly.

Cchart the built-in data processing function is finished. Of course, the function is not too much, will continue to add as needed later.

Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced.

Cchart Daily Lesson--happy started playing against tenth lesson see around corners, Cchart built-in function introduction of data processing