F suffix for floating point.

Okay, I'm a proficient c++ programmer and have been learning Java for only a few weeks now.
I have a question about the f suffix for floating point varibles such as float f = 3.14f;
The f suffix casts this as float right? which is the same as float f = (float) 3.14; Correct?
Why do we have to add the f suffix in the first place? Doesn't the compiler know that we want a float and not a double? (single-precision 32-bit instead of double precision 64 bit) I really do not understand the concept here or why they need the f suffix.
Can someone explain?

ThePHPGuy wrote:
The f suffix denotes that the literal is of a floating-point type.Yes. The d suffix does the same.
Java has two different types of floating-point numbers.Right.
The type double is the default type.Right.
The float type can have a double and a float literal. Is this true or false?No. At least not in any way I understand it.
I think you're confusing two things:
"floating point number" is any number in the IEEE floating point format.
"float" is a datatype holding a 32bit floating point number.
"double" is a datatype holding a 64bit floating point number.
floating point number literals can be either double literals (without suffix or if the "d" suffix is used) or float literals (when the "f" suffix is used).

Similar Messages

Separator for floating point numbers

Hello,
I work with oracle 9 and have a problem with the entry of floating point numbers.
The separator for floating point numbers in my data is a point (5.60).
The pre-setting of oracle is a comma (5,60).
By inserting I get the error message:
01722. 00000 - "invalid number"
How can i change this setting
Thanks for Help
F.

Hi,
I'm not sure if I understood your problem, however the NLS_NUMERIC_CHARACTERS variable specifies the characters to use as the group separator and decimal character.
SQL> create table t1 (val number);
Table created.
SQL> select * from nls_session_parameters;
PARAMETER                      VALUE
NLS_LANGUAGE                   AMERICAN
NLS_TERRITORY                  BRAZIL
NLS_CURRENCY                   R$
NLS_ISO_CURRENCY               BRAZIL
NLS_NUMERIC_CHARACTERS ,.
NLS_CALENDAR                   GREGORIAN
NLS_DATE_FORMAT                DD/MM/YYYY
NLS_DATE_LANGUAGE              AMERICAN
NLS_SORT                       BINARY
NLS_TIME_FORMAT                HH24:MI:SSXFF
NLS_TIMESTAMP_FORMAT           DD/MM/RR HH24:MI:SSXFF
NLS_TIME_TZ_FORMAT             HH24:MI:SSXFF TZR
NLS_TIMESTAMP_TZ_FORMAT        DD/MM/RR HH24:MI:SSXFF TZR
NLS_DUAL_CURRENCY              Cr$
NLS_COMP                       BINARY
NLS_LENGTH_SEMANTICS           BYTE
NLS_NCHAR_CONV_EXCP            FALSE
17 rows selected.
SQL> insert into t1 values (1.50);
1 row created.
SQL> select * from t1;
       VAL
       1,5
SQL> alter session set nls_numeric_characters='.,';
Session altered.
SQL> select * from t1;
       VAL
       1.5Cheers
Legatti

Designing for floating point error

Hello,
I am stuck with floating point errors and I'm not sure what to do. Specifically, to determine if a point is inside of a triangle, or if it is on the exact edge of the triangle. I use three cross products with the edge as one vector and the other vector is from the edge start to the query point.
The theory says that if the cross product is 0 then the point is directly on the line. If the cross product is <0, then the point is inside the triangle. If >0, then the point is outside the triangle.
To account for the floating point error I was running into, I changed it from =0 to abs(cross_product)<1e-6.
The trouble is, I run into cases where the algorithm is wrong and fails because there is a point which is classified as being on the edge of the triangle which isn't.
I'm not really sure how to handle this.
Thanks,
Eric

So, I changed epsilon from 1e-6 to 1e-10 and it seems to work better (I am using doubles btw). However, that doesn't really solve the problem, it just buries it deeper. I'm interested in how actual commercial applications (such as video games or robots) deal with this issue. Obviously you don't see them giving you an error every time a floating point error messes something up. I think the issue here is that I am using data gathered from physical sensors, meaning the inputs can be arbitrarily close to each other. I am worried though that if I round the inputs, that I will get different data points with the exact same x and y value, and I'm not sure how the geometry algorithms will handle that. Also, I am creating a global navigation mesh of triangles with this data. Floating point errors that are not accounted for correctly lead to triangles inside one another (as opposed to adjacent to each other), which damages the integrity of the entire mesh, as its hard to get your program to fix its own mistake.
FYI:
I am running java 1.6.0_20 in Eclipse Helios with Ubuntu 10.04x64
Here is some code that didn't work using 1e-6 for delta. The test point new Point(-294.18294451166435,-25.496614108304477), is outside the triangle, but because of the delta choice it is seen as on the edge:
class Point
     double x,y;
class Edge
     Point start, end;
class Triangle
     Edge[] edges;
     public Point[] getOrderedPoints() throws Exception{
          Point[] points = new Point[3];
          points[0]=edges[0].getStart();
          points[1]=edges[0].getEnd();
          if (edges[1].getStart().equals(points[0]) || edges[1].getStart().equals(points[1]))
               points[2]=edges[1].getEnd();
          else if (edges[1].getEnd().equals(points[0]) || edges[1].getEnd().equals(points[1]))
               points[2]=edges[1].getStart();
          else
               throw new Exception("MalformedTriangleException\n"+this.print());
          orderNodes(points);
          return points;
        /** Orders node1 node2 and node3 in clockwise order, more specifically
      * node1 is swapped with node2 if doing so will order the nodes clockwise
      * with respect to the other nodes.
      * Does not modify node1, node2, or node3; Modifies only the nodes reference
      * Note: "order" of nodes 1, 2, and 3 is clockwise when the path from point
      * 1 to 2 to 3 back to 1 travels clockwise on the circumcircle of points 1,
      * 2, and 3.
     private void orderNodes(Point[] points){
          //the K component (z axis) of the cross product a x b
          double xProductK = crossProduct(points[0],points[0], points[1], points[2]);
          /*        (3)
           *          +
           *        ^
           *      B
           * (1)+             + (2)
           *       ------A-->
           * Graphical representation of vector A and B. 1, 2, and 3 are not in
           * clockwise order, and the x product of A and B is positive.
          if(xProductK > 0)
               //the cross product is positive so B is oriented as such with
               //respect to A and 1, 2, 3 are not clockwise in order.
               //swapping any 2 points in a triangle changes its "clockwise order"
               Point temp = points[0];
               points[0] = points[1];
               points[1] = temp;
class TriangleTest
     private double delta = 1e-6;
     public static void main(String[] args) {
                Point a = new Point(-294.183483785282, -25.498196740397056);
          Point b = new Point(-294.18345625812026, -25.49859505161433);
          Point c = new Point(-303.88217906116796, -63.04183512930035);
          Edge aa = new Edge (a, b);
          Edge bb = new Edge (c, a);
          Edge cc = new Edge (b, c);
          Triangle aaa = new Triangle(aa, bb, cc);
          Point point = new Point(-294.18294451166435,-25.496614108304477);
          System.out.println(aaa.enclosesPointDetailed(point));
      * Check if a point is inside this triangle
      * @param point The test point
      * @return     1 if the point is inside the triangle, 0 if the point is on a triangle, -1 if the point is not is the triangle
      * @throws MalformedTriangleException
     public int enclosesPointDetailed(LocalPose point, boolean verbose) throws Exception
          Point[] points = getOrderedPoints();
          int cp1 = crossProduct(points[0], points[0], points[1], point);
          int cp2 = crossProduct(points[1], points[1], points[2], point);
          int cp3 = crossProduct(points[2], points[2], points[0], point);
          if (cp1 < 0 && cp2 <0 && cp3 <0)
               return 1;
          else if (cp1 <=0 && cp2 <=0 && cp3 <=0)
               return 0;
          else
               return -1;
         public static int crossProduct(Point start1, Point start2, Point end1, POint end2){
          double crossProduct = (end1.getX()-start1.getX())*(end2.getY()-start2.getY())-(end1.getY()-start1.getY())*(end2.getX()-start2.getX());
          if (crossProduct>floatingPointDelta){
               return 1;
          else if (Math.abs(crossProduct)<floatingPointDelta){
               return 0;
          else{
               return -1;
}

Regular Expression for floating point numeric field

Hi,
the requirements for the field are as follows:
- floating point numeric field 7 digits in length
- the field must contain a decimal (dot) and either one, two or three digits to the right of the decimal
- (leading zeroes are required if needed to fill up the 7 characters)
My example shown below does not check for the length of 7 characters:
public static void main(String[] args) {
    String str = "04100.0";
    System.out.println(str);
    Pattern f_1To7 = Pattern.compile("^([0-9]*\\.[0-9]{1,3})$");
    Matcher matcher = f_1To7.matcher(str);
    if (matcher.find()) {
        // yes, we've found something
        System.out.println("We matched the pattern!");
    } else {
        System.out.println("Better luck next time!");
}When changing the pattern to
^([0-9]*\\.[0-9]{1,3}){7}$the whole expression will be repeated 7 times - but I would like to have to whole String to be 7 characters long.
Here are some examples for the field:
050.500 or 04100.0Thanks a lot and best regards,
- Stephan

Jackler wrote:
Perhaps I did not express clearly enough. My problem is not a java issue - what I need is a regular expression (pattern) suiting my requirements:
-floating point numeric field 7 digits in length
-contains a decimal and either one, two or three digits to the right of the decimal
...Assuming that you are going to use Java*, you could use a lookahead at the start of your regex:
"^(?=\\d{4,6}\\.\\d{1,3}$).{8}$"Meaning:
^             # match the start of the string
(?=           #
\d{4,6}     #   ensure that there are between 4 and 6 digits...
\.          #   followed by a DOT...
\d{1,3}     #   followed by 1 to 3 digits
.{8}$         # match exactly 8 characters directly followed by the end of the string* or some other language that has look-ahead support (most PCRE implementations have them)

Byte Order for Floating Point Types

I need to send an array of floating point values from an x86 C++ application to a Java application. I am using a socket to transfer the data. What, if anything, do I have to do about preserving the correct byte order?

Probably nothing.
If you do end up having a problem, look at the java.nio package. Specfically, java.nio.ByteOrder, and java.nio.Double/FloatBuffer.
To be completely safe, I think I'd probably send an enum in some kind of header that indicates what byte order your C++ is sending and use the *Buffer classes to automatically handle the conversion.

Performance for floating point/packed decimal arithmec expressions

Hi,
i need to loop over a big internal table doing some intense mathemtical operations with floating numbers.
The compiler does not allow this:
a = 60.0 * b.
Instead i have to write
a = '60.0' * b.
Now i'm afraid that the string 60.0 is converted to float in every loopstep. This conversion is just wasting of time. Even if i use
a = 60 * b.
there will be a lots of conversions from interger to float.
My first question is if i'm right that '60.0' is converted over and ovber again to float and the second one is how can i avoid that?
My first idea is to define constants with the right type and then use these constants inside the loop avoidung the conversions. Any other ideas, hints, corrections to my assumptions?

i went to SE30 Tips&Tricks and compared
constants:
co_60 type float value '60.0'.
data:
a type float,
b type float.
a = 3.
do 10000 times.
a = b * co_60.
enddo.
with
constants:
co_60 type float value '60.0'.
data:
a type float,
b type float.
a = 3.
do 10000 times.
a = b * '60.0'.
enddo.
there is a significant difference in the runtime. I guess the compiler does not really optimize here.
By the way: i cant understand OSS Note 1465138.... if i have S_DEVELOP i can execute code with se38, its irrelevant id se30 is open for editing or not...i made a copy of rshowtim in D system

Floating Point Representations on SPARC (64-bit architecture)

Hi Reader,
I got hold of "Numerical Computation Guide -2005" by Sun while looking for Floating Point representations on 64 bit Architectures. It gives me nice illustrations of Single and Double formats and the solution for endianness with
two 32-bit words. But it doesn't tell me how it is for 64-bit SPARC or 64-bit x86.
I might be wrong here, but having all integers and pointers of 64-bit length, do we still need to break the floating point numbers and store them in lower / higher order addresses ??
or is it as simple as having a Double Format consistent in the bit-pattern across all the architectures (Intel, SPARC, IBMpowerPC, AMD) with 1 + 11 + 52 bit pattern.
I have tried hard to get hold of a documentation that explains a 64-bit architecture representation of a Floating Point Number. Any suggestion should be very helpful.
Thanks for reading. Hope you have something useful to write back.
Regards,
Regmee

The representation of floating-point numbers is specified by IEEE standard 754. This standard contains the specifications for single-precision (32-bit), and double-precision (64-bit) floating-point numbers (There is also a quad-precision (128-bit) format as well). OpenSPARC T1 supports both single and double precision numbers, and can support quad-precision numbers through emulation (not in hardware). The fact that this is a 64-bit machine does not affect how the numbers are stored in memory.
The only thing that affects how the numbers are stored in memory is endianness. SPARC architecture is big-endian, while x86 is little-endian. But a double-precision floating-point numer in a SPARC register looks the same as a double-precision floating-point number in an x86 register.
formalGuy

Floating-point addition unit

Hello All,
I am very new to NI and I am looking for an example of floating-point addition unit. Basically, I am looking for some example to perform addition of two floating point number (single or double precision). -- just how to create floating-point addition unit using logical gates model (i.e. AND, OR, XOR, etc)
Thank you!
Leo
Message Edited by smuStudent on 12-05-2005 11:51 PM

Most (if not all) of us, when we want to do floating point math just put the Add function onto the block diagram. I would suggest you google for floating point gates or something similar. You can create subVIs that make up the basic functions such as a full adder and then link them together as needed.
Attachments:
Full Adder.JPG ‏9 KB

Can I create a java app for my palm zire 71 that uses floating point calc

I am an eclipse user that is looking at studio creator 2 and was wondering if I could create a java app for my palm zire 71. I have read alot about no floating point support in midp... is that true for java on the palm? If so, how does one calculate with floats and doubles to do sqrt functions etc?
Thanks in advance for your time
Dean-O

I looked at netbeans and it does not support floating points in midlets. Not good for palm app if no floating point ability. J2ME supports floating point but in netbeans... is uses midlets and there are no floating points. Now what does one do? Not that dreaded C++
THanks in advance
Dean-O

32-bit floating point HDR support for LR4.1 RC2

Folks,
In the event you haven't discovered it, LR4.1 RC2 has added support for importing and adjusting a 32-bit floating point TIFF file. Which means LR4 can tonemap an HDR image. To use this, you'll need to use Photoshop's HDR Pro to put together the multiple exposed images, then set the options to make a 32-bit HDR image in HDR Pro and save that as a TIFF file. Then import the TIFF into LR4.1 RC2 for toning...note: nothing you do to the HRD in HDR Pro will impact the 32-bit FP TIFF. If you do some initial adjustments of the original raw files in LR 4.1, I'm pretty sure most of the toning in LR4.1 on the raw files is ignored. But white balance works (haven't tested spot healing and lens corrections yet).
Note, to do the HDR process, the raw images will end up being demosaiced and the saved HDR TIFF will be a linear ProPhoto RGB image.
Try it...the ability to use LR (and eventually ACR–it's not hooked up in the ACR 7 beta yet) to toning HDR images is actually pretty impressive. Also note, that you don't really need to feed HDR Pro a ton of multiple exposures...2 (normal and under to preserve highlight detail) or 3-5 depending on the scene contrast range is all you need. More isn't really better (unless you really need to shoot a very high dynamic range scene...

I will try that in the morning, but when checking the properties today it did say 16-bit for each clip. I have gotten around this by taking each clip offline, opening it in STP, applying the effects, doing a save as and then reconnecting each clip with the new file. It seems to work with no sync issues. Just doesn't work as easily as it should. Ideally I should be able to send each section to an STP script and allow it to do its work and have it work.
I sure hope to find out exactly what is going on.
K

IEEE 754 standards for representing floating point numbers

HI All..
Most of us are not awared how the actually Floating point numbers are represented . IEEE have set standards as how should we represent floating point numbers.
I am giving u the link with which u can know how actually these are represented.
http://en.wikipedia.org/wiki/IEEE_754
If u have any doubts u can always reach me.
Bye
Happy learning
[email protected]

A noble but misguided attempt at dispelling the recurring problems the programmers have over and over again. There have been repeated posts to links about the IEEE standard, to little or no avail. The newbies who run into the problems will continue to do so, without regard to yet another post about it here.

Error in mapping for floating Number calculation

Hi All,
   I have a small doubt in floating number calculation in Mapping.
Actually i am geting a floating point number and calculating the SUM and generating the output. The input is of 2 decimal places(Ex: 26.02 and 26.03 ), but when it is adding all the values it is generating a three digit decimal number (Ex: 52.050003)
I dont know from where it is geting one extra number "2" in the output.
Please find the code for the same and let me know if i need to do something else to get ride of this.
   //write your code here
float sum=0;
if(a != null && a.length > 0.00)
   for ( int j =0; j<a.length;j++)
    sum = sum + Float.parseFloat(a[j]);
   result.addValue(String.valueOf(sum));
else
result.addValue("0");
Thanks in Advance,
JAY

Jay,
Please use the below code and let us know, if it helps.
BigDecimal sum= new BigDecimal("0");
BigDecimal bd;
if(a != null && a.length > 0.00)
for ( int j =0; j<a.length;j++)
bd=new BigDecimal(a[j]);
sum=sum.add(bd);
result.addValue(""+sum+"");
else
result.addValue("0");
in import section - java.math.*;
raj.
Edited by: Raj on Feb 18, 2008 11:11 AM

R6002 - floating point not loaded / C++ Runtime Error

Good Evening,
I have been having this problem with Adobe Bridge for a while and tonight sat down to try and solve it. Fresh version of Windows XP reinstalled all programs and this is still happening! Any Ideas?
This error only occurs with Adobe Bridge, I can load Photoshop etc.. all fine.
Error:
"Runtime Error!
Program: C:\ProgramFiles\Adobe\Adobe Bridge CS3\Bridge.exe
R6002
- floating point not loaded"
Here is a print screen..
http://images.unbrokenphotography.co.uk/BridgeError.jpg

Is there are answer to this problem? This error message is appearing on an entire lab full of computers. We are running Web Premium CS4
I have tried to reset the Bridge Preferences:
Hold down the Ctrl key and click on Bridge icon to start.
Should get a reset window with 3 options.
Choose the first option
I still get "Runtime Error! Program: C:\Prgram Files\Adobe\Adobe Bridge CS4\Bridge.exe R6002 -floating point support not loaded"

Invalid Floating Point Error

I have one Captivate 3 project published as a Stand Alone
project with Flash 8 selected. There are 36 slides, no audio, no
eLearning, SWF size and quality are high.
One person who runs this gets an "Invalid Floating Point"
error when he tries to run it the first time. He is running Windows
XP SP2, Firefox 3.0.4. and Flash Player 10.0.12.36. Other Captivate
projects I've created run fine for him. This one sometimes runs
after the first Error message.
Any thoughts on the cause and fix?
Thanks,
Janet

iMediaTouch probably doesn't support Floating Point formats - it certainly doesn't mention them in the advertising. Try saving your files as 24-bit PCMs, and they should import fine.

Pack and Floating Point Data Type in ABAP

Dear All,
I am new to ABAP. Started with data types. Came across pack and floating point.
Please let me know what PACK and Floating Point stands for with few examples and the main difference between them.
Regards
Arun V

Hi,
You'd better ask this question in ABAP forum http://forums.sdn.sap.com/forum.jspa?forumID=50 .
Best Regards,
Ada

F suffix for floating point.

Similar Messages

Maybe you are looking for