Having trouble with my outputs giving me 4 decimal points when I only want 2?

Question

Hye Sun Choi 2017-8-19

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/353348-having-trouble-with-my-outputs-giving-me-4-decimal-points-when-i-only-want-2

编辑： Walter Roberson 2017-8-20

I'm trying to answer the following homework question:

Write a function called fare that computes the bus fare one must pay in a given city based on the distance travelled. Here is how the fare is calculated: the first mile is $2. Each additional mile up to a total trip distance of 10 miles is 25 cents. Each additional mile over 10 miles is 10 cents. Miles are rounded to the nearest integer other than the first mile which must be paid in full once a journey begins. Children 18 or younger and seniors 60 or older get a 20% discount. The inputs to the function are the distance of the journey and the age of the passenger in this order. Return the fare in dollars, e.g., 2.75 would be the result returned for a 4-mile trip with no discount.

And this is my attempt(where d= distance, a=age):

function cost= fare(d, a)
flat_rate= 2;
if (0<=d) && (d<=10) && (18<a) && (a<60)
    output= flat_rate + (.25*(round(d)-1))
elseif d>10 && (18<a) && (a<60)
    output= flat_rate + (.25*9)+ (.10*(round(d)-10))
elseif (0<=d) && (d<=10) && (18>a || 60<a) 
    output= (flat_rate + (.25*(round(d)-1)))*(.80)
elseif d>10 && (18>a || 60<a)
   output= flat_rate + (.25*9)+ (.10*(round(d)-10))*(.80)
  end

I've been trying to test out some values, and the first one I tried was setting d=4, a=44, which should give the expected output of 2.75. However, my output gives me 2.7500. What could I do to fix my outputs to only two decimal points?

Thanks :)

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Chad Greene 2017-8-19

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/353348-having-trouble-with-my-outputs-giving-me-4-decimal-points-when-i-only-want-2#answer_278565

编辑：Chad Greene 2017-8-19

在 MATLAB Online 中打开

Type

format bank

And then everything will be printed to two-decimal precision until you restart Matlab. Formatting styles are described here.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 2

Image Analyst 2017-8-19

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/353348-having-trouble-with-my-outputs-giving-me-4-decimal-points-when-i-only-want-2#answer_278563

在 MATLAB Online 中打开

Use round():

output = round(output, 2);

2 个评论
显示无隐藏无

Hye Sun Choi 2017-8-19

在 MATLAB Online 中打开

hey, thanks for your answer. Unfortunately, I still get an output of 2.7500... Not quite sure what I'm doing wrong.

 function cost= fare(d, a)
flat_rate= 2;
if (0<=d) && (d<=10) && (18<a) && (a<60)
    output= round(flat_rate + (.25*(round(d)-1)),2)

Image Analyst 2017-8-19

在 MATLAB Online 中打开

That's just how it's displayed. You can use

fprintf('output = %.2f\n', output);

or use format bank, like Chad said below, it you want to keep the full precision but want to leave off the semicolon and have it echo the value to the command line with only 2 decimal places shown.

请先登录，再进行评论。