# Using MATLAB to fit the sequential vegetation growth season curve, and to solve the phenological parameter __rs/envi/idl

Source: Internet
Author: User

As shown in the following figure, for the Hants Harmonic analysis of the single pixels of the vegetation growth season curve, now using a one-element six-time polynomial to fit the curve, and to solve the phenological parameters (beginning and end), in MATLAB programming implementation:

Code:

```Year0=zeros (38998,1);
For i=1:1:38998
if M (i,:) ==0
continue;
End
Corrcoficent=polyfit (x,m (i,:), 6);
N=[corrcoficent (1), Corrcoficent (2), Corrcoficent (3), Corrcoficent (4), Corrcoficent (5), corrcoficent (6), Corrcoficent (7)-shreold (i)];
Year=roots (N);
For J=1:1:6
if Isreal (j) && Year (j) >210 && Year (j) <360
Year0 (i) =year (j);
End-end
fprintf (Num2str (i)); fprintf (' \ n ')
; End
fprintf (' \ n ');
fprintf (' done ');```
Code Explanation:

Train of thought: by means of 38,998 pixels of an existing image, a six-time polynomial is established, and obtain the coefficient, thus obtains the concrete expression of a six times polynomial, and then the days corresponding to the phenological period are reversed by selecting the phenological threshold (the dynamic threshold in Excel) for the number of days to line up the phenology.

1, Year0=zeros (38998,1): Declare an array of 38998 rows 1 columns

2, Corrcoficent=polyfit (X,m (i,:), 6): Get coefficient

3, N: six root

4, Year0 inside Save the final result

Related Keywords:

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

## A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

• #### Sales Support

1 on 1 presale consultation

• #### After-Sales Support

24/7 Technical Support 6 Free Tickets per Quarter Faster Response

• Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.