Calculate taxi fare by giving multiple inputs and single output

Write a function called taxi_fare that computes the fare of a taxi ride. It takes two inputs: the distance in kilometers (d) and the amount of wait time in minutes (t). The fare is calculated like this:

• the first km is $5
• every additional km is $2
• and every minute of waiting is $0.25.

Once a km is started, it counts as a whole (Hint: consider the ceil built-in function). The same rule applies to wait times. You can assume that d >0 and t >= 0 but they are not necessarily integers. The function returns the fare in dollars. For example, a 3.5-km ride with 2.25 minutes of wait costs $11.75. Note that loops and if-statements are neither necessary nor allowed.

[per isakson]

Homework? What have you done so far?

[vignesh suresh]

function fare= taxi_fare(d,t) d=ceil(d),t=ceil(t)
n=1; fare=((d-n)*2+(d/d)*5)+(t*0.25);

[Indrajit Marathe]

function fare= taxi_fare(d,t)
d=ceil(d);
t=ceil(t);
D=ceil(d-1);
fare=5+2*D+0.25*t;
end

[Juhi Shrivastava]

What is the correct solution ?

[Eyobel Gebre]

yep!

[Harsha Vardhan]

Why is (d-1) taken?

Please help, I am a beginner in programming.

[Walter Roberson]

Harsha:

"every additional km" -- that means after the first km. The number of km after the first km is (d-1)

[somnath paul]

function fare= taxi_fare(d_km,t_sec)
d=ceil(d_km);

% d = ceil(d_km) rounds each element of of d_km to the nearest integer greater than or equal to that element.

t=ceil(t_sec);
D=ceil(d-1);

% I had to call another variable D because if i put d instead of D than it represent the input argument 
% but we already taken 5 doller for the first kilometer. so, we need to eliminate that first kilometer.

fare=5+D*2+0.25*t;
end

[Portato Chu]

function fare = taxi_fare(d,t)
fare = distance(d)+waite(t);


end

function costdis = distance(M)
M = ceil(M);
costdis = (M-(M-1))*5 + ((M-1)*2)
end
function costime = waite(N)
N = ceil(N);
costime = N*0.25
end

[SALMA HACHIMY]

what about random input what we gonna do??

[Walter Roberson]

@SALMA HACHIMY

You are going to write correct code so that your code passes automatic grading? That's what you are going to do about random input ?

Answer 1

[Kalpesh Shah]

Its a Simple Question. Use 'ceil' as suggested in hint and it works fine

function fare = taxi_fare(d,t)
d = ceil(d)
t = ceil(t)

fare=5+(2*(d-1))+(t*0.25)

[Risa Dwi Ratnasari]

what is ceil mean?

[Stephen23]

https://www.mathworks.com/help/matlab/ref/ceil.html

This was discussed extensively in the comments to Raj's answer, so you could have found the answer to your question by simply reading this thread.

You could have also found the documentation yourself using any internet search engine.

[Safir Iqbal]

"ceil" is used to roundoff to nearest integer

[Walter Roberson]

ceil does not mean to round off to nearest integer: that would be round()

ceil() means:

• if the value is already an integer, leave it as-is
• otherwise, return the next largest (closer to +infinity) representable integer

For example, -3.2 becomes -3 (next integer that is larger than the number), and +3.2 becomes +4 (next integer that is larger than the number), whereas "round to nearest integer" for +3.2 would be +3.

[samyak doshi]

use ceil function and make sure its ceil(d-1) not ceil(d) as first km is added differently

understand this code...thats more important than just copying it. its a basic code

function fare=taxi_fare(d,t)
D=ceil(d-1);
T=ceil(t);
fare=5+2*D+0.25*T;
end

[Thato Mokhothu]

I have tried this solution and it doesn't work

[Rik]

@Thato Mokhothu Then you should probably do your own homework.

[Quyen Le]

@Thato Mokhothu idk why but you have to arrange like that way : func (1st row), ceil for 2nd and 3rd rows, then the equation in the forth row, then it works :)) i don't really get why it can not run when I let the equation on the 2nd row.

LIke this

function fare = taxi_fare (d,t)
d = ceil(d);
t = ceil(t);
fare = 5 + 2*(d-1) + 0.25*t;
end

Instead Of

function fare = taxi_fare (d,t)
fare = 5 + 2*(d-1) + 0.25*t;
d = ceil(d);
t = ceil(t);
end

[Walter Roberson]

@Quyen Le

Suppose you do

A = 1

A = 1

B = A * 5

B = 5

A = 2

A = 2

After that series of statements, what is B ?

Answer:

B

B = 5

B did not change. When you wrote B = A * 5, you were not creating a formula for B: instead MATLAB copies the current value for A as of the time of the assignment and uses that to calculate B, and after that B has no knowledge of how it got to have the value it has.

If you were writing formulas instead of expressions, then consider the formula

B = B + 1

B = 6

As a formula, it would have to be interpreted as forcing B to be some value such that B and (B+1) were the same value. There are only three values such that B and (B+1) are the same value:

-inf == -inf + 1

ans = logical
   1

inf  ==  inf + 1

ans = logical
   1

[nan, nan+1]

ans = 1×2

NaN NaN

I did not try to compare nan and nan+1 because comparisons with nan are always false.

If we understand

B = B + 1

as copying the current value of B, adding 1, and making the result the new value of B, then we get something that is very useful in programming. But if we think we are writing formulas, that

B = B + 1

is defining a formula saying that B and B + 1 must be the same value, then that is something that has very few uses.

Why does it matter? Well, if you define

fare = 5 + 2*(d-1) + 0.25*t;

and then afterwards change d and t, then if you are defining fare as a formula, it might make sense to change d and t afterwards -- but as the B = B + 1 case shows, expecting those to be formulas is often not very useful. If you instead understand it as copying the current values of d and t and using those to compute fare and then forgetting all information about how that exact value came to be, then when you change d and t afterwards, then those changes to d and t do not matter.

Furthermore, if we were interpreting

fare = 5 + 2*(d-1) + 0.25*t;

as being a formula relating fare to whatever value of d and t existed at the time we asked about the value of fare, then we would also have to understand

d = ceil(d);

as being a formula -- and that is a formula that could only be true if d is already an integer. If the input d were, for example, 3.8, then as a formula

3.8 == ceil(3.8)

would be false, and instead of doing something useful, you could only be telling MATLAB that the function as a whole only applies if d was already an integer... and then what would you expect MATLAB to do if the user wanted to calculate the fare for 3.8 miles ?

Answer 2

[Vijay G]

function fare = taxi_fare(x,y)
   d = 5+(((ceil (x))-1)*2);
   t = ((ceil(y))*.25);
   fare = d+t;
end

letme know whether this helped you. Thanks

Answer 3

[Raj]

Seems quite straightforward. Where exactly are you having problem? Your formulation should look like this:

Fare=5+(2*(d-1))+(t*0.25) % Minimum fare of $5 for first KM plus $2 for every additional KM plus waiting time charge

Just pass the inputs d and t to the function named taxi_fare and use ceil on both before putting them in the above mentioned equation. You will get your fare which you can pass as output of the function. Good luck!!

[Jagmeet Singh]

well i tried your solution, but it does not meet the criteria when distance is 3.5kms and time is 2.25 minutres.

[Jagmeet Singh]

Raj,

your statement gives an answer of 10.5625 when distance d=3.5 and time t=2.25. Whereas in the question it is stated that the value should be 11.75. Could you please help on that. I am thinking maybe we need to round of d and t.

i tried but my statement could be incorrect or i might not be using the correct logic.

Thanks

[Stephen23]

"I am thinking maybe we need to round of d and t."

Your assignment states "Hint: consider the ceil built-in function" Did you try that?

Show us the code that you tried.

[Jagmeet Singh]

function fare=taxi_fare(d,t)

ceil(d)

ceil(t)

fare=5+(2*(d-1))+(t*0.25)

[Stephen23]

@Jagmeet Singh : this line:

ceil(d)

calculates the ceiling of d , displays it in the command window (because this is the default if you do not suppress the output) and then simply discards that value. So you calcuated the ceiling of d but then did not use it in your calculation.

Note that very basic MATLAB concepts, such as how to call functions with outputs, are explained in the introductory tutorials:

https://www.mathworks.com/help/matlab/getting-started-with-matlab.html

[Raj]

Hi,

I have tried the equation with when distance d=3.5 and time t=2.25 it gives the correct value as 11.75$. As explained by Stephen, you have to use the ceil values in your equation. Something like this:

 Dist=ceil(Dist);
 Wait_Time=ceil(Wait_Time)
 Fare=5+(2*(Dist-1))+(Wait_Time*0.25)

[Jagmeet Singh]

@Stephen Cobeldick and @Raj

thank you very much for your support guys.

[Divyang Jain]

Tq RAJ because your answer is correct

[Tereza Vondrova]

can you write the whole code down please, it is still not work for me :////

[Swathi D]

what does this ceil function do?

[Walter Roberson]

https://www.mathworks.com/help/matlab/ref/ceil.html

[Stephen23]

"what does this ceil function do?"

https://en.wikipedia.org/wiki/Floor_and_ceiling_functions

[Selvakumar T]

why d-1??

[Walter Roberson]

The first kilometer is a particular price. Additional kilometers are a different price. Additional kilometers beyond the first kilometer would be expressed by subtracting the first kilometer from the distance traveled to get additional kilometers.

[Ivonne Ordoñez]

función tarifa = taxi_fare (d, t)
Recorridos=('primero'; 'segundo'; 'tercero')
d = (3.5; 3.1; 13)
y = redondo (d)
t = (2.25; 0; 0.6)
Y = redondo (t)
T=table(Recorridos,d,t)
primerkm=5
kmadic = 2
tesp = 0.25
tarifa = primerkm + ((Td) -1) * kmadic + Tt * .tesp
fin
% Yo tengo esto pero me marca un error "Expresión no válida. Al llamar a una función o indexar una variable, use paréntesis. De lo contrario, verifique si hay delimitadores no coincidentes.

[Walter Roberson]

What is the purpose of the table T ? The question does not ask you to display anything.

The calculations should not round() any component: ceil() is more appropriate.

[Sejal Syed]

Doesnt work tried it

[Walter Roberson]

Sejal Syed please explain what it was you tried, and what error you encountered.

Answer 4

[amjad khan]

function fare=taxi_fare(distance,time)
    distance=ceil(distance-1)
    time=ceil(time)
    fare=5*(2+(distance-1)+0.25*time
end
 % "d"can be used instead of distance and "t" instead of time,

[Walter Roberson]

I would not think that they want the temporary values such as distance to be displayed.

[Jessika Lisboa]

Why it needs to be (distance-1)?? I dont understand, can you please help me?

Thank you

[Walter Roberson]

the first km is in the base price. You need to calculate "additional" kilometres, after the first, so you subtract the 1 initial kilometre

Answer 5

[Arooba Ijaz]

function [fare] =taxi_fare (d,t)
a=ceil(d)
b=ceil(t)
fare=(b*0.25)+((a-1)*2)+5
end

Answer 6

[AYUSH MISHRA]

function fare= taxi_fare(d,t)
d=ceil(d);      %d=total distance cover by taxi
t=ceil(t);       %t=total time taken to complete distance 
RD=ceil(d-1);     %RD= remaning distace after 1 km distance
fare=5+2*RD+0.25*t;%fare=1st km charge + Remaning km Distance charge + waiting time charge
end

solution of question

fare=taxi_fare(3.5,2.25)

fare =

   11.7500

[DGM]

After the first line, d is an integer, so d-1 is also an integer. Using ceil() on d-1 does nothing.

I'll give you credit for using comments though. That's good.

Answer 7

[Dante Gallo Torres]

You can use matrix for this problem:

function fare = taxi_fare(d, t)
fare = [1 ceil(d-1) ceil(t)] * [5; 2; 0.25]
end

[Rik]

Neat solution to 'hide' the addition in the matrix product. The only things missing in your answer are documentation of this function and a semicolon.

Answer 8

[Roweida Bawab]

function fare = taxi_fare(d, t)
d = ceil(d);
t = ceil(t);
fare = 5 + (d-1)*2 + t*0.25
end

Answer 9

[muyiwabowen]

function rare = taxi_fare(d,t)
rare = 5 + 2*ceil((d-1)) + 0.25*ceil(t);
end

Answer 10

[Muhammad Talha Malik]

can anyone tell me what is wrong with this code?

function fare = taxi_fare(d,t)
fare = (5+2*(d-1))+0.25*d;
end

[Walter Roberson]

You are multiplying the waiting time price 0.25 by the distance rather than the time waited

Waiting time needs to be calculated in whole minutes

kilometres needs to be calculated in whole kilometres.

If the distance is less than 1 km your code would use a negative value, d-1

[RAHWA ZESLUS]

how can i solve rondom input?

[Walter Roberson]

@RAHWA ZESLUS by writing correct code?

What happens when you test your code with random input? Is it giving the same answer you get when you manually calculate for the same input?

Answer 11

[Stavan]

I wrote this code for the test, but somehow it isnt working with the test, i am getting the right answers but it isnt letting me pass, can anyone show what could be the problem

function total_taxi=taxi_fare(d,t)
total_taxi= 5+2*ceil(d-1)+0.25*ceil(t)
end

[Walter Roberson]

What feedback are you getting from the grader?

To confirm, you are asked to handle the same 5/2/0.25 as asked in the Question posted here?

[Walter Roberson]

Your calculation is wrong for distance values in the range 0 (exclusive) to [eps(1/4)+eps(eps(1/4))] . For values in that range, d-1 becomes -1 because of floating point double precision limitations . The question permits you to assume d>0 but a distance of (for example) 1 femtometre is > 0 and so fair game for the purposes of the question.

[Stavan]

okay so what should be written instead of -1 according to you

Also the grader just says the answer is incorrect, even though the code works and gives out correct answers

[Walter Roberson]

add (d>=1) .* kilometer_cost instead of kilometer_cost

Answer 12

[Karan]

I would say this code is more general and can be use for any km if not counted as a whole number, like one can use it for 0.5km.

function fare = taxi_fare(d, t)
d = ceil(d);
t = ceil(t);
fare = 5*(d - (d-1)) + (d-1)*2 + t*0.25
end