i am trying to get my function to work.
The values for "time" and "value" are taken from a raw data txt file (time and value are raw data parsed by my programm).
Just for the purpose of demonstration i chose diffrent values for time and value.
I can also get other calculations to work, i just have a problem with getting my Log fn to work.
%Declaration (a time between 0-60s, a value between 0-200)
ti= (0.5);
q = (3);
L1 = 3/(log10(2));%9.9658
L2 = log10(2/3); %-0.17609
time = 40 %anything between 0 and 60
value = 90 %anything between 0 and 200
%f2 = Log Function
f2=figure(2);
y2= 9.9658*log10(1/(time*value*0.5*10*-0.17609));
x2=time;
fplot(x2,y2);
xlabel('Time in s'), ylabel('Value in db'),title('Calculations'),set(gca,'fontsize',15); grid on
The result i get is:
error: Question: operator *: nonconformant arguments (op1 is 38x1, op2 is 38x1)
error: called from
Question at line 11 column 5
if anyone had this error before i would be thankfull for help.
Best regards
The Answer to this question is as Cris Luengo pointed out in his answer to boot up a clean Octave session and change "fplot" to "plot".
plot(x2,y2); %works now
Big Thanks!
Related
x = fopen('pm10_data.txt');
fseek(x, 8,0);
dat = fscanf (x,'%f',[2,1000]);
dat = transpose(dat);
a = dat(:,1);
b = dat(:,2);
[r,p] = cor_test (a,b)
fclose(x);
r
p
this is what i got,
r =
scalar structure containing the fields:
method = Pearson's product moment correlation
params = 76
stat = 6.2156
dist = t
pval = 2.5292e-08
alternative = !=
Run error
error: element number 2 undefined in return list
error: called from
tester.octave at line 7 column 6
Presumably you're referring to the cor_test function from the statistics package, even though you don't show loading this in your workspace.
According to the documentation of cor_test:
The output is a structure with the following elements:
PVAL The p-value of the test.
STAT The value of the test statistic.
DIST The distribution of the test statistic.
PARAMS The parameters of the null distribution of the test statistic.
ALTERNATIVE The alternative hypothesis.
METHOD The method used for testing.
If no output argument is given, the p-value is displayed.
This seems to be what you're getting too.
If you want the p value explicitly from that structure, you can access that as r.pval
The syntax [a, b, ...] = functionname( args, ... ) expects the function to return more than one argument, and capture all the returned arguments into the named variables (i.e. a, b, etc).
In this case, cor_test only returns a single argument, even though that argument is a struct (which means it has fields you can access).
The error you're getting effectively means you requested a second output argument p, but the function you're using does not return a second output argument. It only returns that struct you already captured in r.
I am relatively new to python and I am working on creating a program in my fun time to automatically generate a sales sheet. It has several functions that pull the necessary data from a database, and reportlab and a few other tools to place the results onto the generated pdf. I am trying to round the results coming from the Mysql server. However, I have hit a point where I am stuck and all the ways I have tried to round the results throw an error code and do not work. I need a few examples to look at so I can see how this would work and any relevant feedback that would help me learn.
I have tried to use the mysql round function to round the results but that failed. I have also tried to round the results as part of the function that generates the unit cost itself. However, that has failed as well.
A large amount of the code has been deleted due to the security hole it would generate. Code provided is to show what I have done so far. Print result line is to verify that the code is working during development. It is not throwing any erroneous results and will be removed during the last stage of the project.
def upcpsfunc(self, upc):
mycursor = self.mydb.cursor()
command = "Select Packsize from name"" where UPC = %(Upc)s"
mycursor.execute(command, {'Upc': upc})
result = mycursor.fetchone()
print(result[0])
return result[0]
def unitcost(self,upc):
#function to generate unit cost
mycursor = self.mydb.cursor()
command = "Select Concat((Cost - Allow)/Packsize) as total from name
where UPC = %(Upc)s"
mycursor.execute(command, {'Upc': upc})
result = mycursor.fetchone()
print (result[0])
return result[0]
As for the expected results, I would prefer the mysql command round the results before it sends it to Reportlab for placement. So far the results are 4 or 5 digits, which is not ideal. I want the results to have two decimal places, since it would be money. The desired output is 7.50 instead 7.5025
The round function can be used to round numbers:
>>> round(7.5025, 2)
7.5
To get the extra 0 on the end, you can use the following code:
>>> def round_money(n):
s = str(round(n, 2))
if len(s) == 1: # exact dollar
return s + ".00"
elif len(s) == 3: # exact x10 cents
return s + "0"
return s
>>> round_money(6)
'6.00'
>>> round_money(7.5025)
'7.50'
Note that this function returns a string, because 7.50 cannot be represented by an integer in python.
Just as an alternative way to the one already provided, you can do the same thing with string formatting (it'll truncate the decimals though, so you can still round beforehand):
>>> '{:,.2f}'.format(0)
'0.00'
>>> '{:,.2f}'.format(15342.62412)
'15,342.62'
Hopefully a simple question with Lua. I have a problem accessing JSON data. I write the following:
item3 = decoded.items[1].rights
local myText = display.newText(sceneGroup, item3, 150, 80, native.systemFont, 16 )
myText:setFillColor( 1, 1, 1 )
But error comes up
C:\Users\...\data_workingbasics.lua:57: bad argument #2 to 'newText' (string expected, got table)
stack traceback:
[C]: in function 'newText'
I think the problem is JSON data looks like below and I don't know how to fetch this data with square brackets.
Do you know how to write the right path?
"rights":["http://creativecommons.org/licenses/by-nc-sa/4.0/"],
By the way, I also tried item3 = decoded.items[1].rights[0] but get the following error:
C:\Users\...\data_workingbasics.lua:57: bad argument #2 to 'newText' (string expected, got nil)
stack traceback:
[C]: in function 'newText'
Many thanks!
It may be item3 = decoded.items[1].rights["rights"]. If not, use some old-fashioned debugging and add print statements to display properties of the table. For example:
print(#decoded.items[1].rights)
Or iterate through the tables keys and values to see its structure:
for k, v in pairs(decoded.items[1].rights) do
print(k, v)
end
Determine what you are working with.
I am doing this question via an Online learning platform, and there are test cases assigned which i must pass. The topic is Higher Order Functions.
Here is the question:
Write a function make_decimal_to_n_ary_converter that accepts a number n where 1 < n < 17, and returns a number converter that converts a given decimal number into that of base n.
Below is my code(I am supposed to use an inner function i.e converter(x))
def make_decimal_to_n_ary_converter(n):
def converter(x):
if x==0 or x==1:
return x
i=x
b=('A','B','C','D','E','F')
result = ""
while i>0:
a=i%n #3
if a<10:
result = str(i%n)+result
else:
d=a-10
result = b[d] + result
i=i//n
return result
return converter
#Lines below are not to be changed, part of qn
decimal_to_binary = make_decimal_to_n_ary_converter(2)
decimal_to_octal = make_decimal_to_n_ary_converter(8)
decimal_to_hexadecimal = make_decimal_to_n_ary_converter(16)
Here are some test cases that my code passes:
decimal_to_binary(213)
11010101
decimal_to_octal(213)
325
decimal_to_hexadecimal(213)
D5
make_decimal_to_n_ary_converter(15)(213)
E3
However, my code fails some private test cases, and feedback that i received was that my logic in the while loop is wrong. However, after printing some numbers, i failed to see anything wrong.
Would appreciate any help, thank you!
Solved it. My mistake was that for base cases x , i had to return a string instead.
I have a table with rows containing the following numbers:
4191808.51
3035280.22
3437796.06
4013772.33
1740652.56
0
The sum of that table is 16419309.68.
When I do a Linq SUM query on that table, it returns a whole different number: 19876858.14
The code I use to do the sum is as follows:
IEnumerable<MyData> data = _myRepository.GetMatching(myValue);
decimal sumSales = data.Sum(x => x.Sales);
What could be causing this? I suspect some max decimal value but couldn't find info on that
can you please examine your
IEnumerable<MyData> data = _myRepository.GetMatching(myValue);
in the debugger after the execution. I'm suspecting that you are selecting some different set of data - not what you have shown in the sample. I attempted to recreated you situation LinqPad, but constantly getting the correct answer.
decimal[] data = {
4191808.51m
,3035280.22m
,3437796.06m
,4013772.33m
,1740652.56m
,0m
};
decimal sumSales = data.Sum();
sumSales.Dump();
and getting: 16419309.68