Delphi Floating Point Error
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Delphi Floating Point Division By Zero
ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack invalid floating point operation delphi Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Fixing Floating Point Error up vote 2 down vote favorite 1 floating point rounding error I have some code that gets the leading value (non-zero) of a Double using normal math instead of String Math... For Example: 0.020 would return 2 3.12 would return 3 1000 should return 1 The code I have at the moment is: LeadingValue := Trunc(ResultValue * Power(10, -(Floor(Log10(ResultValue))))) However when ResultValue is 1000 then LeadingValue ends up as 0. What can I do to fix this problem I'm assuming
Floating Point Relative Error
is being caused by floating point errors? Thanks. delphi floating-accuracy share|improve this question asked May 30 '10 at 23:19 HannesNZ 9011 add a comment| 4 Answers 4 active oldest votes up vote 1 down vote I'm curious as to why you can't / won't use String manipulation for this. Could you explain further? The most obvious thing you can do to fix the problem is to convert the number to a String and find the first non zero digit. share|improve this answer answered May 30 '10 at 23:44 awmross 2,04122040 String Math would slow it down a lot, this needs to be a fast routine. –HannesNZ May 31 '10 at 0:00 How much performance improvement is there? Just curious, as log, exp and FP in general is not fast either. –awmross May 31 '10 at 4:43 You are loosing the game at "convert the number to a string". As soon as the floating point number is represented as an mantissa + exponent, you've lost the precision. –gabr May 31 '10 at 6:40 @HannesNZ: floating point numbers cannot be represented exactly as decimal string values and vice versa. So either use strings for everything, or be prepared
: Extended; Description The strtofloat function converts a number string, FloatString such as '123.456' into an Extended floating point number. It supports integer, floating point, floating point exception error and scientific (exponent) formats. If a decimal point appears in floating point error matlab FloatString, then it must match the current DecimalSeparator value. Version 2 of this function is for
Floating Point Error Calculator
use within threads. You furnish the FormatSettings record before invoking the call. It takes a local copy of global formatting variables that make the routine thread safe. Notes http://stackoverflow.com/questions/2940704/fixing-floating-point-error The EConvertError exception is thrown if there are errors in FloatString, such as trailing blanks or invalid decimal characters. Related commands Extended The floating point type with the highest capacity and precision FloatToStr Convert a floating point value to a string FloatToStrF Convert a floating point value to a string with formatting TFormatSettings A record for holding http://www.delphibasics.co.uk/RTL.asp?Name=strtofloat locale values for thread-safe functions Author links Buy Website Traffic at Buywebsitetrafficexperts.com Buy Proxies atBuyproxies.io Download this web site as a Windows program. Example code : Converting a scientific format number string var stringValue : string; floatValue: Extended; begin// Set up the source string containing a number representation stringValue := '123.456E+002'; // Convert it to a floating point number floatValue:= strtofloat(stringValue); // And display the value ShowMessage(stringValue+' = '+FloatToStr(floatValue)); end; Show full unit code 123.456E+002 = 12345.6 Example code : Catching string conversion errors var A : Extended; begin// We will catch conversion errors tryA := strtofloat('10 E 2');// Middle blanks are not supported except on Exception : EConvertError do ShowMessage(Exception.Message); end; tryA := strtofloat('$FF');// Hexadecimal values are not supported except on Exception : EConvertError do ShowMessage(Exception.Message); end; end; Show full unit code '10 E 2' is not a valid floating point value '$FF' is not a valid floating point value Delphi Programming © Neil Moffatt 2002 - 2016. All rights reserved.|Contact the author|Home Page
Programming logic Looping SubRoutines Exception handling Dates and times Files Pointers Printing text and graphics Object Orientation basics http://www.delphibasics.co.uk/Article.asp?Name=Numbers Memory leaks! Inheritance Abstraction Interfaces An example class References Standard components Articles Learn to program in Pascal - online education course Castalia for Delphi https://www.experts-exchange.com/questions/20121185/how-to-stop-floating-point-overflow.html A brief history of Delphi Usability : file handling Usability : reference books Author links Buy Website Traffic at Buywebsitetrafficexperts.com Buy Proxies atBuyproxies.io Integer floating point and floating point numbers The different number types in DelphiDelphi provides many different data types for storing numbers. Your choice depends on the data you want to handle. In general, smaller number capacities mean smaller variable sizes, and faster calculations. Ideally, you should use a type that comfortably copes delphi floating point with all possible values of the data it will store. For example, a Byte type can comfortably hold the age of a person - no-one to date has lived as long as 255 years.With decimal numbers, the smaller capacity types also have less precision. Less numbers of significant digits. Let us look at the different types:TypeStorage sizeRange
Byte 1 0 to 255
ShortInt 1-127 to 127
Word 2 0 to 65,535
SmallInt 2 -32,768 to 32,767
LongWord 4 0 to 4,294,967,295
Cardinal 4*0 to 4,294,967,295
LongInt4-2,147,483,648 to 2,147,483,647
Integer4* -2,147,483,648 to 2,147,483,647
Int648-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
Single 4 7significant digits, exponent -38 to +38
Currency 850+ significant digits, fixed 4 decimal places
Double 815significant digits, exponent-308 to +308
Extended1019significant digits, exponent -4932 to +4932
* Note : the Integer and Cardinal types are both 4 bytes in size at present (Delphi release 7), but are not guaranteed to be this size in the future. All other type sizes are guaranteed.<
for Help Receive Real-Time Help Create a Freelance Project Hire for a Full Time Job Ways to Get Help Ask a Question Ask for Help Receive Real-Time Help Create a Freelance Project Hire for a Full Time Job Ways to Get Help Expand Search Submit Close Search Login Join Today Products BackProducts Gigs Live Careers Vendor Services Groups Website Testing Store Headlines Experts Exchange > Questions > how to stop floating point overflow? Want to Advertise Here? Solved how to stop floating point overflow? Posted on 2001-05-20 Delphi 1 Verified Solution 10 Comments 2,442 Views Last Modified: 2012-08-13 I write the formula and had a floating point overflow upon execution/running of the program. Any suggestions experts? InterestRate := ((((exp(iPeriod-1)*ln(1+PeriodInterest))) - 1)/PeriodInterest); Result: interestrate; thks 0 Question by:rhapsody7 Facebook Twitter LinkedIn Google Best Solution byDevice_Diver I think you better check to assure that PeriodInterest differs from 0. Also change all of your floating point vars to double. Add a breakpoint just before the problematic lines and check which numbers Go to Solution 10 Comments LVL 22 Overall: Level 22 Delphi 17 Message Expert Comment by:mnasman2001-05-20 Hello You have to initialize your variables befor your using them if you use your experssion like this InterestRate := ((((exp(iPeriod-1)*ln(1+PeriodInterest))) - 1)/PeriodInterest); it's will give you the error overflow, just initialize your variables, it will work fine iPeriod := 5646; PeriodInterest:=424; InterestRate := ((((exp(iPeriod-1)*ln(1+PeriodInterest))) - 1)/PeriodInterest); Mohammed 0 Message Author Comment by:rhapsody72001-05-20 Hey, What does the numbers 5646, and 424 represent? Also, I did assigned the variable but not sure where to intialise the variables? should it be in the public or the private section? function TFormDataEntry.CalInterest(DepositAmount: currency; I