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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
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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)& x3 j! Z8 O$ L6 |& s
%MMINTERP 1-D Table Search by Linear Interpolation." z# C) n+ M: ~: n7 Q% I
% Y=MMINTERP(TAB,COL,VAL) linearly interpolates the table( H% p" X7 ^; x- G, Y
% TAB searching for the scalar value VAL in the column COL.
# Y% `4 e- c4 L7 a; w# Z* y7 \% All crossings are found and TAB(:,COL) need not be monotonic.
9 H9 {- ^ V. i% M5 y% Each crossing is returned as a separate row in Y and Y has as: g! h. d; o+ S7 R5 o* c' g
% many columns as TAB. Naturally, the column COL of Y contains) t: b* y k2 `) J4 v3 w w
% the value VAL. If VAL is not found in the table, Y=[].' m: c8 V: T6 f8 r, p
3 S% D% f7 x5 j0 f% D.C. Hanselman, University of Maine, Orono ME, 04469
& D! e f; W( u0 S2 _4 L! q8 r% 1/26/946 x* n- I% a _9 O5 _0 | A1 x- Q
% Copyright (c) 1996 by Prentice-Hall, Inc.
# J% u+ |% m, r" o0 i2 E$ q* A! p; M, B* O, p( P% O) @( U
[rt,ct]=size(tab);
, ~$ g; M+ Y5 iif length(val)>1, error('VAL must be a scalar.'), end
( _. f. _0 m" `( D0 _if col>ct|col<1, error('Chosen column outside table width.'), end
. {/ y: P+ L2 }# aif rt<2, error('Table too small or not oriented in columns.'), end( j& g6 Z6 D7 |- m) A/ c
above=tab(:,col)>val;3 Q, k: }- z3 b9 j" E
below=tab(:,col)<val;) g v* R0 D( q/ |
equal=tab(:,col)==val;
$ b4 w" V* ^! ^0 ~( \( |if all(above==0)|all(below==0), % handle simplest case
# M/ ~! Z ?7 X! ^1 M9 g y=tab(find(equal), ;
( F1 L) j: u! L2 H% h0 u. E return
C1 J, P, Z& F L+ Zend
c" V$ x n8 ]9 N' Ipslope=find(below(1:rt-1)&above(2:rt)); %indices where slope is pos' y& v8 I6 U, W( D3 s% e9 J* C
nslope=find(below(2:rt)&above(1:rt-1)); %indices where slope is neg- F* [# j K( W7 g6 d7 n- h
1 X0 o* I8 {. k3 }7 X0 b7 qib=sort([pslope;nslope+1]); % put indices below in order4 n- e+ d% v: p j
ia=sort([nslope;pslope+1]); % put indices above in order& y Z3 Y+ Q1 k0 k
ie=find(equal); % indices where equal to val
0 G, |; {# \% i1 B9 \" j- |" B# v( @* f- ?3 W# M. A! J
[tmp,ix]=sort([ib;ie]); % find where equals fit in result7 B& [; V& o+ X5 g' S
ieq=ix>length(ib); % True where equals values fit2 @$ T/ D6 j: r2 R3 [7 \6 f
ry=length(tmp); % # of rows in result y
4 Y4 H/ |- v% P
l0 W1 s' _9 Q1 g% \1 B) ^1 [0 Zy=zeros(ry,ct); % poke data into a zero matrix
- ^( x6 f7 l2 h+ L/ v( H/ y
0 l- | S$ S: M" k; `) M/ n: jalpha=(val-tab(ib,col))./(tab(ia,col)-tab(ib,col));' D$ C$ H) o$ s$ {: c
alpha=alpha(:,ones(1,ct));
. w0 F) T0 ^% m" a9 M4 D: ?y(~ieq, =alpha.*tab(ia, +(1-alpha).*tab(ib, ; % interpolated values
4 R1 ~' h ]2 B, L1 y/ y4 M$ v
# B3 V1 S! A9 qy(ieq, =tab(ie, ; % equal values, d. N- V5 z0 d
y(:,col)=val*ones(ry,1); % remove roundoff error |
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