Re: [R] Is there lazy copy in R?
On Tue, Dec 15, 2009 at 10:32 PM, hadley wickham h.wick...@gmail.com wrote: I don't understand what these addresses mean. Would you please help me understand it? Did you try reading the documentation? When an object is traced any copying of the object by the C function ‘duplicate’ or by arithmetic or mathematical operations produces a message to standard output. The message consists of the string ‘tracemem’, the identifying strings for the object being copied and the new object being created, and a stack trace showing where the duplication occurred. ‘retracemem()’ is used to indicate that a variable should be considered a copy of a previous variable (e.g. after subscripting). The message consists of the string ‘tracemem’, the identifying strings for the object being copied and the new object being created, and a stack trace showing where the duplication occurred. I tried to read the document before I posted, but wasn't be able to understand it, because there are multiple ways to parse it. To make sure that I understand, I rewrite the above sentence to the following. Is it correct? The message consists of the string ‘tracemem’, the string indicating the object being copied, the string indicating the new object being created, and a stack trace showing where the duplication occurred. I also didn't see a stack trace in my example. If I didn't see Martin Morgan's post, I will still be confused. I thought that there should be only one coping. Why there are two lines? tracemem[0x05cf2798 - 0x05cf2750]: tracemem[0x05cf2750 - 0x05ed8ba0]: __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Is there lazy copy in R?
On Wed, 16 Dec 2009, Peng Yu wrote: On Tue, Dec 15, 2009 at 10:32 PM, hadley wickham h.wick...@gmail.com wrote: I don't understand what these addresses mean. Would you please help me understand it? Did you try reading the documentation? When an object is traced any copying of the object by the C function ‘duplicate’ or by arithmetic or mathematical operations produces a message to standard output. The message consists of the string ‘tracemem’, the identifying strings for the object being copied and the new object being created, and a stack trace showing where the duplication occurred. ‘retracemem()’ is used to indicate that a variable should be considered a copy of a previous variable (e.g. after subscripting). The message consists of the string ‘tracemem’, the identifying strings for the object being copied and the new object being created, and a stack trace showing where the duplication occurred. I tried to read the document before I posted, but wasn't be able to understand it, because there are multiple ways to parse it. To make sure that I understand, I rewrite the above sentence to the following. Is it correct? The message consists of the string ‘tracemem’, the string indicating the object being copied, the string indicating the new object being created, and a stack trace showing where the duplication occurred. I also didn't see a stack trace in my example. If I didn't see Martin Morgan's post, I will still be confused. The stack trace is there, it's just that it is empty because you aren't in a function. I thought that there should be only one coping. Why there are two lines? tracemem[0x05cf2798 - 0x05cf2750]: tracemem[0x05cf2750 - 0x05ed8ba0]: There are two lines because there are two copies. One is the lazy copy because the object is modified, the other is because it is converted from integer to numeric. The whole point of tracemem() is to show copies that you didn't expect, so being surprised by it is a good thing. -thomas Thomas Lumley Assoc. Professor, Biostatistics tlum...@u.washington.eduUniversity of Washington, Seattle __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Is there lazy copy in R?
2009/12/15 tlum...@u.washington.edu: On Wed, 16 Dec 2009, Peng Yu wrote: On Tue, Dec 15, 2009 at 10:32 PM, hadley wickham h.wick...@gmail.com wrote: I don't understand what these addresses mean. Would you please help me understand it? Did you try reading the documentation? When an object is traced any copying of the object by the C function ‘duplicate’ or by arithmetic or mathematical operations produces a message to standard output. The message consists of the string ‘tracemem’, the identifying strings for the object being copied and the new object being created, and a stack trace showing where the duplication occurred. ‘retracemem()’ is used to indicate that a variable should be considered a copy of a previous variable (e.g. after subscripting). The message consists of the string ‘tracemem’, the identifying strings for the object being copied and the new object being created, and a stack trace showing where the duplication occurred. I tried to read the document before I posted, but wasn't be able to understand it, because there are multiple ways to parse it. To make sure that I understand, I rewrite the above sentence to the following. Is it correct? The message consists of the string ‘tracemem’, the string indicating the object being copied, the string indicating the new object being created, and a stack trace showing where the duplication occurred. I also didn't see a stack trace in my example. If I didn't see Martin Morgan's post, I will still be confused. The stack trace is there, it's just that it is empty because you aren't in a function. I thought that there should be only one coping. Why there are two lines? tracemem[0x05cf2798 - 0x05cf2750]: tracemem[0x05cf2750 - 0x05ed8ba0]: I still don't understand what the numbers after 'tracemem[' are. Could somebody please explain it? x=1:3 tracemem(x) [1] 0x1056ef8 x[[4]]=8#I still don't understand what '0x9ac9f0' means here tracemem[0x1056ef8 - 0x9ac9f0]: tracemem(x)#The address of 'x' is 0x9aca38 but not '0x9ac9f0' [1] 0x9aca38 There are two lines because there are two copies. One is the lazy copy because the object is modified, the other is because it is converted from integer to numeric. The whole point of tracemem() is to show copies that you didn't expect, so being surprised by it is a good thing. -thomas Thomas Lumley Assoc. Professor, Biostatistics tlum...@u.washington.edu University of Washington, Seattle __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Is there lazy copy in R?
On Tue, 15 Dec 2009, Peng Yu wrote: 2009/12/15 tlum...@u.washington.edu: On Wed, 16 Dec 2009, Peng Yu wrote: On Tue, Dec 15, 2009 at 10:32 PM, hadley wickham h.wick...@gmail.com wrote: I don't understand what these addresses mean. Would you please help me understand it? Did you try reading the documentation? When an object is traced any copying of the object by the C function ‘duplicate’ or by arithmetic or mathematical operations produces a message to standard output. The message consists of the string ‘tracemem’, the identifying strings for the object being copied and the new object being created, and a stack trace showing where the duplication occurred. ‘retracemem()’ is used to indicate that a variable should be considered a copy of a previous variable (e.g. after subscripting). The message consists of the string ‘tracemem’, the identifying strings for the object being copied and the new object being created, and a stack trace showing where the duplication occurred. I tried to read the document before I posted, but wasn't be able to understand it, because there are multiple ways to parse it. To make sure that I understand, I rewrite the above sentence to the following. Is it correct? The message consists of the string ‘tracemem’, the string indicating the object being copied, the string indicating the new object being created, and a stack trace showing where the duplication occurred. I also didn't see a stack trace in my example. If I didn't see Martin Morgan's post, I will still be confused. The stack trace is there, it's just that it is empty because you aren't in a function. I thought that there should be only one coping. Why there are two lines? tracemem[0x05cf2798 - 0x05cf2750]: tracemem[0x05cf2750 - 0x05ed8ba0]: I still don't understand what the numbers after 'tracemem[' are. Could somebody please explain it? They are the printed representations of the pointers to the objects on the R heap. In practice, they will be base-16 representations of the memory addresses (though the C standard doesn't guarantee this). The one before the - is the address of the object being copied; the one after the - is the address of the copy. The point is to give names to each object, since they need not be R variables and may not have any other name. In this trace you can see that the second copy is of the object created in the first copy. -thomas Thomas Lumley Assoc. Professor, Biostatistics tlum...@u.washington.eduUniversity of Washington, Seattle __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Is there lazy copy in R?
On Tue, Dec 15, 2009 at 2:34 PM, Peng Yu pengyu...@gmail.com wrote: 2009/12/15 tlum...@u.washington.edu: On Wed, 16 Dec 2009, Peng Yu wrote: On Tue, Dec 15, 2009 at 10:32 PM, hadley wickham h.wick...@gmail.com wrote: I don't understand what these addresses mean. Would you please help me understand it? Did you try reading the documentation? When an object is traced any copying of the object by the C function ‘duplicate’ or by arithmetic or mathematical operations produces a message to standard output. The message consists of the string ‘tracemem’, the identifying strings for the object being copied and the new object being created, and a stack trace showing where the duplication occurred. ‘retracemem()’ is used to indicate that a variable should be considered a copy of a previous variable (e.g. after subscripting). The message consists of the string ‘tracemem’, the identifying strings for the object being copied and the new object being created, and a stack trace showing where the duplication occurred. I tried to read the document before I posted, but wasn't be able to understand it, because there are multiple ways to parse it. To make sure that I understand, I rewrite the above sentence to the following. Is it correct? The message consists of the string ‘tracemem’, the string indicating the object being copied, the string indicating the new object being created, and a stack trace showing where the duplication occurred. I also didn't see a stack trace in my example. If I didn't see Martin Morgan's post, I will still be confused. The stack trace is there, it's just that it is empty because you aren't in a function. I thought that there should be only one coping. Why there are two lines? tracemem[0x05cf2798 - 0x05cf2750]: tracemem[0x05cf2750 - 0x05ed8ba0]: I still don't understand what the numbers after 'tracemem[' are. Could somebody please explain it? x=1:3 tracemem(x) [1] 0x1056ef8 x[[4]]=8#I still don't understand what '0x9ac9f0' means here tracemem[0x1056ef8 - 0x9ac9f0]: tracemem(x)#The address of 'x' is 0x9aca38 but not '0x9ac9f0' [1] 0x9aca38 Hi Thomas, The address of x after 'x[[4]]=8' is '0x9ac9f0'. Why the last 'tracement(x)' gives '0x9aca38'? There are two lines because there are two copies. One is the lazy copy because the object is modified, the other is because it is converted from integer to numeric. The whole point of tracemem() is to show copies that you didn't expect, so being surprised by it is a good thing. -thomas Thomas Lumley Assoc. Professor, Biostatistics tlum...@u.washington.edu University of Washington, Seattle __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
[R] Is there lazy copy in R?
I'm wondering if lazy copy is available in R or not. For example, in the following code, I'm wondering if the memory for y is allocated in the 2nd line or the 3rd line. Is there a documentation for this? x=1:1 y=x y[[10]]=5 __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Is there lazy copy in R?
use tracemem() to figure out... and read its documentation in detail. b On Dec 15, 2009, at 1:03 AM, Peng Yu wrote: I'm wondering if lazy copy is available in R or not. For example, in the following code, I'm wondering if the memory for y is allocated in the 2nd line or the 3rd line. Is there a documentation for this? x=1:1 y=x y[[10]]=5 __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Is there lazy copy in R?
a=1:10 b=a a=1:10 tracemem(a)# I assume the following is address 'a' points to [1] 0x05cf2798 b=a b[1]=1 tracemem[0x05cf2798 - 0x05cf2750]: tracemem[0x05cf2750 - 0x05ed8ba0]: I don't understand what these addresses mean. Would you please help me understand it? On Mon, Dec 14, 2009 at 9:23 PM, Benilton Carvalho bcarv...@jhsph.edu wrote: use tracemem() to figure out... and read its documentation in detail. b On Dec 15, 2009, at 1:03 AM, Peng Yu wrote: I'm wondering if lazy copy is available in R or not. For example, in the following code, I'm wondering if the memory for y is allocated in the 2nd line or the 3rd line. Is there a documentation for this? x=1:1 y=x y[[10]]=5 __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Is there lazy copy in R?
I don't understand what these addresses mean. Would you please help me understand it? Did you try reading the documentation? When an object is traced any copying of the object by the C function ‘duplicate’ or by arithmetic or mathematical operations produces a message to standard output. The message consists of the string ‘tracemem’, the identifying strings for the object being copied and the new object being created, and a stack trace showing where the duplication occurred. ‘retracemem()’ is used to indicate that a variable should be considered a copy of a previous variable (e.g. after subscripting). Hadley -- http://had.co.nz/ __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] Is there lazy copy in R?
It means that R does have the lazy copy mechanism, which I didn't know, and I think it can be very useful to make R running more quickly. On Tue, Dec 15, 2009 at 12:15 PM, Peng Yu pengyu...@gmail.com wrote: a=1:10 b=a a=1:10 tracemem(a)# I assume the following is address 'a' points to [1] 0x05cf2798 b=a b[1]=1 tracemem[0x05cf2798 - 0x05cf2750]: tracemem[0x05cf2750 - 0x05ed8ba0]: I don't understand what these addresses mean. Would you please help me understand it? __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
