I need to give my variable a value from SQL, this part of the code it's where the compiler stops, aparently it's maybe a convertion problem. In my database that column is designed as float.
float presion = safe_cast<float>(data[4]);
Here is the code, every value gets to his variable until it reaches the floats
This is my database, the value of 1.5 should go to the variable
safe_cast is not a standard c++ type casting.
If you change your code to:
float presion = dynamic_cast<double>(data[4]);
it should work.
I solved the issue, I'm gonna post it here anyway for other people with the same problem.
Just change, float for double:
float presion = safe_cast<float>(data[4]);
For :
float presion = safe_cast<double>(data[4]);
Related
I have a simple FMU file which contains a sine block that takes u as input and outputs y. In this case, u is set to equal to time. In my C++ code I have loaded the FMI library from FMILibrary and had done all the necessary steps up to a point where I want to give my input u a new value of pi(as 3.14). So I went:
fmistatus = fmi2_import_set_real(fmu, &uRef, 1, &pi);
while (timeCurrent < timeEnd){
fmistatus = fmi2_import_do_step(fmu, timeCurrent , stepSize, fmi2_true);
timeCurrent += stepSize;
}
u was still set to time even though I tried to give it a new value. Did I miss something?
PS. Is there anywhere I can find a more detailed description on the FMI library functions? Currently I can only find input output descriptions or did I miss something again.
UPDATE: After a few trials, I think this issue might be because I was trying to redefine my equation u = time. In other words when I change my u variable into RealInput block in openmodelica everything goes fine. So what if I really wants to redefine a certain equation? what do I have to do?
You shall not be able to set any variable in FMI - and especially not a variable with a binding equation - and I assume your Modelica model has "u=time;". Instead of having "u=time" you need to add a top-level input without any equation (so that the exported FMI has it as an input) - and then connect that to the sine-block.
Details:
For a co-simulation FMI the restriction on what you can set are in the state-diagram in section 4.2.4 of FMI2 specification.
Between fmi2DoStep you can only set Real variables that have causality="input" or causality="parameter" and variability="tunable" - and an input with an equation doesn't qualify.
Before starting the integration you could set it for other variables as well, but that is only guess-values for the initialization - and should not over-write the "u=time" equation.
I want to change text into float number for calculation in Qt
float test = ui.tableWidget->item(0, 1)->text().replace(",", ".", Qt::CaseSensitive).toFloat();
when I type 2.86, actually I see test = 2.85999990 in debug. How can I receive correctly what i typed ?
I can use this for showing
qDebug() << QString::number( test, 'f', 2 );
But I want a value for calculation, not for showing.
As #hauron already said this is format specific but normal behaviour. You might want to take a read on this.
Additionally you might also take a look at another answer here. Using some additional library may work for you, if applicable.
I am doing some maths on the GPU and reading the result.
And I am getting the wrong value From log. I have verified this for values 0 - 10, 20, 30, 40.
If I hard code the value (as you can see bellow under verify) I get the right result spat out. However if I use log with the hard coded value that should return the same result, I get the wrong result spat out.
This is the kind of thing I have been doing in my function.
vec4 IScale(vec4 value)
{
switch(uScaleType_i)
{
case Log:
//value = log(value);
value = vec4(1,1,1,1);
value.r = log(5);
//verifiy
//value.r = 0.698970004
break;
case Sqrt:
value = sqrt(value);
break;
case None:
break;
}
return value;
}
I am wondering is there any sense here. I have added the results of what I am getting back into excel and done a graph. At first Its almost like its double the correct value but its not quite that clean, it gets further and further away.
Is there any other explanation for this other than a driver issue? I cant think of anything else to check!
And if so how can i possibly work around it, other than refactoring my code to do it on the CPU? And why can't I find evidence online to back this up? I am completely utterly baffled!
I am running on a laptop with:
(Intel(R) HD Graphics 4000 with 132 ext.)
p.s. Sqrt is fine and I get the values I would expect.
p.p.s I checked, I have not accidentally created a function called "log"
I believe you are tripping over the base used for the log. In Excel the base is 10 however in glsl it is e.
To get the right result you should divide the result with the log of the base you want.
value = log(value)/log(10);
Or in excel you can use LN(RC[-1])
This is as per the specification. log() will return the natural logarithm, i.e. the logarithm to the base e. Not the base 10 logarithm.
I am facing some strange behaviour appearing only on some notebook.
I am developing in c++ using msvc 2012 and the qt framework.
I will try to sum up the problem and i am hoping that someone has any idea what the problem could be or what i could try to find out..
Generally it's the following problem:
void myclass::foo()
{
const double value1 = 100.0;
double value2;
value2 = some_function_returning_double();
if(value1 > value2)
{
//__ do something
}
}
The problem is that the condition fails as the local variable gets overwritten.
If I do some debug output i can see that variable value1 is not 100.0 anymore but some random value .. so that the comparison randomly fails ..
One thing i figured out is that everything just works fine if i don't use local variables. If i set up value1 and value2 as member variables of my class everything works without problems, but that can't be the solution.
Now the strange thing is that this error does only occur on some notebook (some mobile i5 cpu).
On my machine (i5) and on many other notebooks (even other mobile i5) everything just works fine.
I know that you won't be able to solve my problem with this little information i can offer here, but maybe some of you has any hint what the problem could be and what i could try to solve this.
Many thanks in advance.
In visual studio 2012, add a data breakpoint (debug->new breakpoint->new data breakpoint) on the address of the variable that gets overwritten.
First, break at the start of the function.
Then set the data breakpoint: just type &value1 in the "New breakpoint` the input box.
Then it should break just after the value has been modified, and you should see the culprit.
Data breakpoints are a very powerful tool, that helped me found nasty bugs very quickly.
I tried this because I want to learn how to grab a machine unique ID.
I need it because I'm gonna code a program that reads the machineid and compares it to a specific one.
I edited the code(in the end, the code that prints the Machine ID) to this:
string MachineID;
MachineID = vtProp.bstrVal;
if (MachineID == vtProp.bstr)
but it only gives me this error.
How would I make my HWID variable be set to the value of vtProp.bstrVal, then compare it with vtProp.bstrVal? I've googled for some hour now, can't seem to get it fixed.
Thanks in advance!
Simple syntax error - you've used =, which is assignment, instead of ==, which is comparison.
Because c++ accepts nonboolean types in if statements, the code if(variable = value) is acceptable to the compiler, which tries to assign MachineID the value of vtProp.bstr, which causes your error due to type mismatch.