In the following octave code, the condition in the while statement is not being evaluated as expected.
The condition in the while statement is always evaluating as "TRUE" even if the value of "stop_training" is being printed as the number 0.
What could be wrong with the statement?
stop_training = 0;
C = 1;
while (! stop_training) %NOT operator is not working
C = input("Enter the value for C:");
if(length(C)==0)
C=1;
endif
fprintf("Using C = %d\n", C);
A = C+1;
stop_training = yes_or_no("continue to train the model?");
fprintf("you chose: %d\n", stop_training);
pause;
endwhile
Related
I was trying to run the program but the window says
error: 'a' undefined near line 2, column 10
error: called from
false_position at line 2 column 6
here's my code
function y = false_position(f, a, b, error)
if ~(f(a) < 0)
disp("f(a) must be less than 0")
elseif ~(f(b) > 0)
disp("f(b) must be greater than zero")
else
c = 100000;
while abs(f(c)) > error
%Formula for the x-intercept
c = -f(b) * (b - a) / (f(b) - f(a)) + b;
if f(c) < 0
a = c;
else
b = c;
endif
disp(f(c))
endwhile
x = ["The root is approximately located at ", num2str(c)];
disp(x)
y = c;
endif
endfunction
every time i ran the code, it says like that and i am not really a pro with using the octave. I was kinda hoping someone will help me with this error.
Any answers will do
How can I make a function with a vector as input and a matrix as an output?
I have to write a function that will convert cubic meters to liters and English gallons. The input should be a vector containing volume values in m ^ 3 to be converted. The result should be a matrix in which the first column contains the result in m ^ 3, the second liter, the third English gallon.
I tried this:
function [liter, gallon] = function1 (x=[a, b, c, d]);
liter= a-10+d-c;
gallon= b+15+c;
endfunction
You're almost there.
The x=[a,b,c,d] part is superfluous, your argument should be just x.
function [liter, gallon] = function1 (x);
a = x(1); b = x(2); c = x(3); d = x(4);
liter = a - 10 + d - c;
gallon = b + 15 + c;
endfunction
If you want your code to be safe and guard against improper inputs, you can perform such checks manually inside the function, e.g.
assert( nargin < 1 || nargin > 4, "Wrong number of inputs supplied");
The syntax x=[a,b,c,d] does not apply to octave; this is reserved for setting up default arguments, in which case a, b, c, and d should be given specific values that you'd want as the defaults. if you had said something like x = [1,2,3,4], then this would be fine, and it would mean that if you called the function without an argument, it would set x up to this default value.
I am new to this, and I am looking for help. I currently am stuck in a program I'm trying to complete. Here it is:
def printStock(stockList, stockPrice, p):
for i in range(len(stockPrice)):
if stockPrice[i] > p:
p = stockList[i]
print("The stocks with a higher value are:", p)
def searchStock(stockList, stockPrice, s):
for i in range(len(stockList)):
if s == stockList[i]:
s = stockPrice[i]
elif s != stockList[i]:
s = -1
return s
def mainFun():
stockList= []
stockPrice = []
l = 1
while l > 0:
stocks = str(input("Enter the name of the stock:"))
stockList += [stocks]
if stocks == "done"or stocks == 'done':
l = l * -1
stockList.remove("done")
else:
price = int(input("Enter the price of the stock:"))
stockPrice += [price]
l = l + 1
print(stockList)
print(stockPrice)
s = input("Enter the name of the stock you're looking for:")
searchStock(stockList, stockPrice, s)
p = s
printStock(stockList, stockPrice, p)
Every time I run the program to the end, it never returns the variable s for some reason. If i replace return with print, it always prints -1 instead of the stockPrice if its on the list. I also get an error saying "unorderable types int() > str()" regarding line 3. Basically the function printStock takes the three parameters and once the function is done it should print the names of the stocks higher than the value 'p'. The value of 'p' is the same as the value I get after calling searchStock function, but I cant seem to get it to work. Can someone please help me?
s is being returned from the function, but the return value is not being assigned to any variable on the outer scope.
Just replace
searchStock(stockList, stockPrice, s)
with
s=searchStock(stockList, stockPrice, s)
And everything should work as expected
I have a function filledFunction() that returns a float filled:
float filledFunction(){
if (FreqMeasure.available()) {
sum = sum + FreqMeasure.read();
count = count + 1;
if (count > 30) {
frequency = FreqMeasure.countToFrequency(sum / count);
a = frequency * x;
b = exp (a);
c = w * b;
d = frequency * z;
e = exp (d);
f = y * e;
float filled = c + f;
sum = 0;
count = 0;
return filled;
}
}
}
When I call this function with
while (1){
fillLevel = filledFunction();
int tofill = 500 - fillLevel;
Serial.print("fillLevel: ");
Serial.println(fillLevel);
Serial.print("tofill: ");
Serial.println(tofill);
The serial monitor should output two numbers that add up to 500 named fillLevel and tofill. Instead I get a repeating sequence of similar values:
http://i.imgur.com/Y9Wu8P2.png
The First two values are correct (410.93 + 89 = 500), but the following 60ish values are unknown to me, and do not belong there.
I am using an arduino nano
The filledFunction() function only returns a value if FreqMeasure.available() returns true AND count > 30. As stated in the answers to this question the C89, C99 and C11 standards all say that the default return value of a function is undefined (that is if the function completes without executing a return statement). Which really means that anything could happen, such as outputting arbitrary numbers.
In addition, the output that you're seeing starts off 'correct' with one of the numbers subtracted from 500, even when they have weird values such as 11699.00 and -11199 (which equals 500 - 11699.00). However, lower down in the output this seems to break down and the reason is that on Arduino Nano an int can only hold numbers up to 32767 and therefore the result of the subtraction is too big and 'overflows' to be a large negative number.
Fixing the filledFunction() function to explicitly return a value even if FreqMeasure.available() is false or count <= 30 and ensuring that it can't return a number greater than 500 will likely solve these issues.
Ackermann's Function is a recursive mathematical algorithm that can be used to test how well a computer performs recursion. Design a function ackermann(m,n), which solves Ackermann's Function. Use the following logic in your function:
If m = 0, then return n + 1
If n = 0 then return ackermann(m-1, 1)
Otherwise, return ackermann(m-1, ackermann(m, n-1))
The program stops after it hits 13. Can anyone tell me what I have done wrong?
declare main()
declare ackermann(m:int, n:int)
openconsole
main()
print:print "Press any key to quit...",
do:until inkey$<>""
closeconsole
end
sub main()
def counter, m, n:int
counter = 0
for counter = 1 to 100
print ackermann(counter)
next counter
return
sub ackermann(m, n)
if m = 0
return = n + 1
else
if n = 0
return = ackermann(m - 1, 1)
else
return = ackermann(m - 1, ackermann(m, n - 1))
endif
endif
return
Your print statement is
print ackermann(counter)
but your function is
sub ackermann(m, n)
You need to send a second parameter in the first call.
Do note that Ackermann's function grows incredibly quickly - values above m,n > (3,4) are going to have a LOT of digits and if you go more than even about (4,4) you'll quickly find numbers that could quite possibly fill up your memory entirely with digits...
Refer to Wikipedia to see the magnitude of the numbers you are trying to compute...
declare main()
declare ackermann(m:int, n:int)
openconsole
main()
print:print "Press any key to quit...",
do:until inkey$<>""
closeconsole
end
sub main()
print Ackermann(3,5)
return
sub ackermann(m, n)
if m = 0
return = n + 1
else
if n = 0
return = ackermann(m - 1, 1)
else
return = ackermann(m - 1, ackermann(m, n - 1))
endif
endif
return