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TA的每日心情 | 开心 2014-9-21 08:29 |
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签到天数: 19 天 [LV.4]偶尔看看III
- 自我介绍
- 我思我在
群组: 数学建模 群组: 中国矿业大学数学建模协会 群组: 数学趣味、游戏、IQ等 群组: 南京邮电大学数模协会 群组: LINGO |
function y=mminterp(tab,col,val)
& P6 @6 I* a7 M%MMINTERP 1-D Table Search by Linear Interpolation.
( h, D- b& f9 i( K% Y=MMINTERP(TAB,COL,VAL) linearly interpolates the table
1 ?$ U1 w+ s$ N9 H1 x, ?% TAB searching for the scalar value VAL in the column COL.
" x2 F* e0 I2 i# v1 i- Z9 n9 b- i% All crossings are found and TAB(:,COL) need not be monotonic.
6 h7 C/ b. A8 c% Each crossing is returned as a separate row in Y and Y has as8 s. t$ J7 F9 @6 B
% many columns as TAB. Naturally, the column COL of Y contains5 w% Y0 Q0 p$ q# P5 X8 p! [( q
% the value VAL. If VAL is not found in the table, Y=[].
+ F/ r$ W% Q- n/ y$ ^0 \/ J8 s9 P9 ~( L* c+ Q
% D.C. Hanselman, University of Maine, Orono ME, 04469
5 u; F! _2 d' K5 W- Y/ W) Z6 q% 1/26/94
0 F/ w3 h( \5 N% i0 }- f& H% Copyright (c) 1996 by Prentice-Hall, Inc.
: N. \0 I6 U% [& d) t
1 W; o( }; j @) ]. `" l' b[rt,ct]=size(tab);
% X, l8 Y$ U9 G! H4 bif length(val)>1, error('VAL must be a scalar.'), end
* b& d% }( O( Z3 M6 X3 wif col>ct|col<1, error('Chosen column outside table width.'), end6 f" ~) E# z, `" K
if rt<2, error('Table too small or not oriented in columns.'), end' V8 j( w0 ?8 A
above=tab(:,col)>val;/ d5 i! B, f5 Y
below=tab(:,col)<val;% ~' N) v8 a3 W6 _) M
equal=tab(:,col)==val;: w. J. v* X$ ]& S+ Q0 C
if all(above==0)|all(below==0), % handle simplest case
0 G: b4 v- f' F: ~: T. \ y=tab(find(equal), ;% N6 }" r9 v3 f- Q( ?1 F2 y
return( n: M9 W n8 W
end' D, {8 v+ _* _: n) G& H f" k, {
pslope=find(below(1:rt-1)&above(2:rt)); %indices where slope is pos9 B2 L J0 T6 b4 M% l6 D4 I6 q
nslope=find(below(2:rt)&above(1:rt-1)); %indices where slope is neg7 ~/ z2 g |+ M4 T. o2 h
' u- |0 e V- M, F# O
ib=sort([pslope;nslope+1]); % put indices below in order& h$ d9 s: N, O, a
ia=sort([nslope;pslope+1]); % put indices above in order& r/ R% t4 b/ W# L/ g2 ^; W
ie=find(equal); % indices where equal to val3 A! n) J( e8 u" u' a! @
0 e/ z* o5 A6 Y# w[tmp,ix]=sort([ib;ie]); % find where equals fit in result5 v( F5 T0 \5 E' i9 X1 T# E
ieq=ix>length(ib); % True where equals values fit
' \" u# E2 O: A4 d! V' Lry=length(tmp); % # of rows in result y
$ F% C1 S/ F. j3 ]# Z7 E% h0 A. I# G+ v+ a8 K
y=zeros(ry,ct); % poke data into a zero matrix
G. R7 a7 p3 {, j# {, F9 D5 D T) h
+ M1 v } z2 s9 Nalpha=(val-tab(ib,col))./(tab(ia,col)-tab(ib,col));' @0 _2 }2 n& n* h7 @" i
alpha=alpha(:,ones(1,ct));5 E2 q. d% O6 [
y(~ieq, =alpha.*tab(ia, +(1-alpha).*tab(ib, ; % interpolated values
! Q6 R! K( p5 N b& w
, U+ T3 @7 i8 \$ }( m8 Iy(ieq, =tab(ie, ; % equal values! B! d E0 S& R+ I, L6 z) m
y(:,col)=val*ones(ry,1); % remove roundoff error |
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