DAQ not enough precision


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DAQ very not convenient .If using big bit calculate ...

0xffff*2^48 + 0xffff*2^32 + 0xffff*2^16 + 0xffff

In this case calculate isn't correct...Please fix it in next version...It let me every day headache...

By the way,I hope DAQ calculate can support more than 64 bit...

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DAQFactory uses 64 bit double precision floats for all floating point operations and 32 bit signed integers for all bit operations. For most this is almost too much precision as most people only need a few decimals of precision in their floating point values. To increase the precision would decrease the performance of the application. We cannot increase the integer precision because the numbers are stored in the double format, so a 64 integer will not fit.

Until all users are running 64 bit operating systems it is likely that the precision will remain the same. I am sorry for the inconvenience, but we cannot make such a drastic change that would affect the performance for all our users.

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We use double internal for all numbers, but double is only 52 bit precision. The remaining bits are used for sign and exponent. Since we use exclusively doubles for data storage, there is no way to store a 64 bit integer. Visual Studio and I suppose CX-Programmer presumably use an integer data type for their 64 bit integers, but we only have doubles and so this is not an option. We will consider offering a 64 bit option in release 6.0, perhaps by using higher precision floating points internally instead of doubles, but this is not a minor change. I appreciate you advice, but at this point there is nothing we can do but to offer you ways around it.

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