How can I make this loop work?

1 次查看（过去 30 天）
KAI YIN CHAN
KAI YIN CHAN 2016-7-18
评论： KAI YIN CHAN 2016-7-18
I want to create a function that can translate text input to morse code. But I am suck in the loop. e.g.
>> morserOutputFile('AB')
c =
1
c =
2
morsecode =
.-
Here is the code
function morserOutputFile(text)
Dit = '.';
ssp = ' ';
Dah = '-';
% Defining Characters & Numbers
A = strcat(Dit,ssp,Dah);
B = strcat(Dah,ssp,Dit,ssp,Dit,ssp,Dit);
C = strcat(Dah,ssp,Dit,ssp,Dah,ssp,Dit);
D = strcat(Dah,ssp,Dit,ssp,Dit);
E = strcat(Dit);
F = strcat(Dit,ssp,Dit,ssp,Dah,ssp,Dit);
G = strcat(Dah,ssp,Dah,ssp,Dit);
H = strcat(Dit,ssp,Dit,ssp,Dit,ssp,Dit);
I = strcat(Dit,ssp,Dit);
J = strcat(Dit,ssp,Dah,ssp,Dah,ssp,Dah);
K = strcat(Dah,ssp,Dit,ssp,Dah);
L = strcat(Dit,ssp,Dah,ssp,Dit,ssp,Dit);
M = strcat(Dah,ssp,Dah);
N = strcat(Dah,ssp,Dit);
O = strcat(Dah,ssp,Dah,ssp,Dah);
P = strcat(Dit,ssp,Dah,ssp,Dah,ssp,Dit);
Q = strcat(Dah,ssp,Dah,ssp,Dit,ssp,Dah);
R = strcat(Dit,ssp,Dah,ssp,Dit);
S = strcat(Dit,ssp,Dit,ssp,Dit);
T = strcat(Dah);
U = strcat(Dit,ssp,Dit,ssp,Dah);
V = strcat(Dit,ssp,Dit,ssp,Dit,ssp,Dah);
W = strcat(Dit,ssp,Dah,ssp,Dah);
X = strcat(Dah,ssp,Dit,ssp,Dit,ssp,Dah);
Y = strcat(Dah,ssp,Dit,ssp,Dah,ssp,Dah);
Z = strcat(Dah,ssp,Dah,ssp,Dit,ssp,Dit);
period = strcat(Dit,ssp,Dah,ssp,Dit,ssp,Dah,ssp,Dit,ssp,Dah);
comma = strcat(Dah,ssp,Dah,ssp,Dit,ssp,Dit,ssp,Dah,ssp,Dah);
question = strcat(Dit,ssp,Dit,ssp,Dah,ssp,Dah,ssp,Dit,ssp,Dit);
slash_ = strcat(Dah,ssp,Dit,ssp,Dit,ssp,Dah,ssp,Dit);
n1 = strcat(Dit,ssp,Dah,ssp,Dah,ssp,Dah,ssp,Dah);
n2 = strcat(Dit,ssp,Dit,ssp,Dah,ssp,Dah,ssp,Dah);
n3 = strcat(Dit,ssp,Dit,ssp,Dit,ssp,Dah,ssp,Dah);
n4 = strcat(Dit,ssp,Dit,ssp,Dit,ssp,Dit,ssp,Dah);
n5 = strcat(Dit,ssp,Dit,ssp,Dit,ssp,Dit,ssp,Dit);
n6 = strcat(Dah,ssp,Dit,ssp,Dit,ssp,Dit,ssp,Dit);
n7 = strcat(Dah,ssp,Dah,ssp,Dit,ssp,Dit,ssp,Dit);
n8 = strcat(Dah,ssp,Dah,ssp,Dah,ssp,Dit,ssp,Dit);
n9 = strcat(Dah,ssp,Dah,ssp,Dah,ssp,Dah,ssp,Dit);
n0 = strcat(Dah,ssp,Dah,ssp,Dah,ssp,Dah,ssp,Dah);
text = upper(text);
vars ={'period','comma','question','slash_'};
morsecode='';
a = length(text);
i = length(text);
while a > 0
c=(i-a)+1
switch c
case text(c)=='A'
morsecode = strcat(morsecode,A);
case text(c)=='B'
morsecode = strcat(morsecode,B);
case text(c)=='C'
morsecode = strcat(morsecode,C);
case text(c)=='D'
morsecode = strcat(morsecode,D);
case text(c)=='E'
morsecode = strcat(morsecode,E);
case text(c)=='F'
morsecode = strcat(morsecode,F);
end
a = a-1;
end
display(morsecode);

请先登录，再回答此问题。

回答（1 个）

Walter Roberson
Walter Roberson 2016-7-18
Use an ascending for loop instead of a descending while loop.
Your code could be much more efficient if you used a cell array.
targets = ['A' : 'Z', '.,?/', '0' : '9'];
morse_translations = {A, B, C, D, .... };
[tf, idx] = ismember(text(c), targets);
if tf
this_code = morse_translations{idx};
...
end
  1 个评论
KAI YIN CHAN
KAI YIN CHAN 2016-7-18
Thank you so much! Especially for showing how I can make it more efficient.

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Box Plots 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by