Hi,

i was wondering - when will float be supported by Value?
(couldn't find it in the roadmap)

in the interrim - is there a bazar or patch thingy one could point me to?

thanks in advance

--m

having a flot in memory - writing it out through value/json , then reading it again incurs a conversion and its not the same number - ( i guess on a personal level i am probably puzzled how this is not bothering you - but thats beside the point)

Hi,

I could see some benefit for supporting float in Value too. (I do signal processing with floats, so they frequently end up in various locations in my code.)
Having Value supporting float and EditFloat/EditFloatSpin added would allow cleaner code with dialogs.

Currently I have to round the float value to a clean double with roundr() to avoid excessive decimal places in EditDouble/EditDoubleSpin display. Also, when reading the value out from EditDouble/EditDoubleSpin, I will need to cast first to (double) and only thereafter to (float).

As an example, I have filtering frequencies controlled with:

void SetHPF(float fc);
float GetHPF();

Filling the EditDoubleSpin:

hpf<<=roundr(GetHPF(),3);

Hi,

The following code portrays the float rounding issue:

#include <Core/Core.h>

using namespace Upp;

CONSOLE_APP_MAIN
{
	Value v(0.002f);
	Cout() << v << "\n";
	Cout() << FormatDouble(v) << "\n";
	Cout() << FormatG(v,7) << "\n";
}

The result of running the above follows:

0.0020000000949949
0.0020000000949949
0.002
<--- Finished, press [ENTER] to close the window --->

I do not know how to solve this cleanly. In any case a regular user seeing 0.002000000095 in a field where he expects to see 0.002, will not be happy about it. For years I have used roundr() all over the code to fix this up, but having a solution hidden in Core would be awesome!

Best regards,

Tom

OK, here's an idea to handle the EditDouble/EditDoubleSpin rounding issue. Adding something like:

hpf.Pattern("%.7g");

to the constructor of the dialog. This will yield possibly sufficient rounding to the float value being represented as double to avoid excessive decimals.

Hi,

The following code portrays the float rounding issue:

#include <Core/Core.h>

using namespace Upp;

CONSOLE_APP_MAIN
{
	Value v(0.002f);
	Cout() << v << "\n";
	Cout() << FormatDouble(v) << "\n";
	Cout() << FormatG(v,7) << "\n";
}

The result of running the above follows:

0.0020000000949949
0.0020000000949949
0.002
<--- Finished, press [ENTER] to close the window --->

I do not know how to solve this cleanly. In any case a regular user seeing 0.002000000095 in a field where he expects to see 0.002, will not be happy about it. For years I have used roundr() all over the code to fix this up, but having a solution hidden in Core would be awesome!

Best regards,

Tom

	double x = 0.002;
	DDUMP(x);
	float fx = x;
	x = fx;
	DDUMP(x);

That said, all of this made me think that if we knew that it is float in Value, we might be able to apply for something like FormatG(v,7) instead when displaying it (e.g. in EditDouble).

const dword FLOAT_V  = 13;

Hi Mirek,
Quote:

That said, all of this made me think that if we knew that it is float in Value, we might be able to apply for something like FormatG(v,7) instead when displaying it (e.g. in EditDouble).

Would that involve introducing:

const dword FLOAT_V  = 13;

and 'DOUBLE_V' -like processing for it, except when putting it out in FormatG() and friends?

This is in some ways pretty much what I attempted to do with the above "float Value prototype" above, but that is really bad as I do not really understand all the details of Value. You may wish to take a look anyway -- and then trash it.

Best regards,

Tom

No problem... I trust you will soon come up with some astonishingly smart three line solution for the task!

Best regards,

Tom

Tom1 wrote on Sat, 02 April 2022 13:31

No problem... I trust you will soon come up with some astonishingly smart three line solution for the task!

Best regards,

Tom

Nothing too smart for now, but I have added ConvertFloat and EditFloat.

The jury is still out for float in Value.... do not want to do that now. It feels like while it fixes some issues (e.g. Value->JSON conversion when the values went through float precision), there might be many caveats.

operator float() const           { return Is(DOUBLE_V) ? (float)GetSmallRaw<double>() : (float)GetOtherDouble(); }

typedef WithSpin<float, EditFloat>			 EditFloatSpin;
typedef WithSpin<float, EditFloatNotNull>	 EditFloatNotNullSpin;

// And then some magic to make those two working and visible in layout editor.