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  • Convert object to DateRange

    - by user655832
    I'm querying an underlying PostgreSQL database using Pandas 0.8. Pandas is returning the DataFrame properly but the underlying timestamp column in my database is being returned as a generic "object" type in Pandas. As I would eventually like to seasonal normalization of my data I am curious as to how to convert this generic "object" column to something that is appropriate for analysis. Here is my current code to retrieve the data: # get records from db example import pandas.io.sql as psql import psycopg2 # define query to get all subs created this year QRY = """ select i i, i * random() f, case when random() > 0.5 then true else false end t, (current_date - (i*random())::int)::timestamp with time zone tsz from generate_series(1,1000) as s(i) order by 4 ; """ CONN_STRING = "host='localhost' port=5432 dbname='postgres' user='postgres'" # connect to db conn = psycopg2.connect(CONN_STRING) # get some data set index on relid column df = psql.frame_query(QRY, con=conn) print "Row count retrieved: %i" % (len(df),) Thanks for any help you can render. M

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  • 284 GiB of data, 217.4 GiB of space

    - by Malfist
    I want to reinstall my OS, but I don't have the hard drive space to backup any more (I have a RAID 1 array, so I haven't done it for a while). In my /home I have 284.8 GiB of data, and I have a spare 250 GB (or 217.4 GiB) hard drive that I've been using for backup. What type of compression algorithm (if any) is capable of this type of compression? I don't care about the time, I have a quad core though, so something that utilizes all 4 cores would be great. I have tried 7zip with no success. Ran on one core for two days and failed because of lack of space. Any ideas?

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  • Roguelike FOV problem

    - by Manderin87
    I am working on a college compsci project and I would like some help with a field of view algorithm. I works mostly, but in some situations the algorithm sees through walls and hilights walls the player should not be able to see. void cMap::los(int x0, int y0, int radius) { //Does line of sight from any particular tile for(int x = 0; x < m_Height; x++) { for(int y = 0; y < m_Width; y++) { getTile(x,y)->setVisible(false); } } double xdif = 0; double ydif = 0; bool visible = false; float dist = 0; for (int x = MAX(x0 - radius,0); x < MIN(x0 + radius, m_Height); x++) { //Loops through x values within view radius for (int y = MAX(y0 - radius,0); y < MIN(y0 + radius, m_Width); y++) { //Loops through y values within view radius xdif = pow( (double) x - x0, 2); ydif = pow( (double) y - y0, 2); dist = (float) sqrt(xdif + ydif); //Gets the distance between the two points if (dist <= radius) { //If the tile is within view distance, visible = line(x0, y0, x, y); //check if it can be seen. if (visible) { //If it can be seen, getTile(x,y)->setVisible(true); //Mark that tile as viewable } } } } } bool cMap::line(int x0,int y0,int x1,int y1) { bool steep = abs(y1-y0) > abs(x1-x0); if (steep) { swap(x0, y0); swap(x1, y1); } if (x0 > x1) { swap(x0,x1); swap(y0,y1); } int deltax = x1-x0; int deltay = abs(y1-y0); int error = deltax/2; int ystep; int y = y0; if (y0 < y1) ystep = 1; else ystep = -1; for (int x = x0; x < x1; x++) { if ( steep && getTile(y,x)->isBlocked()) { getTile(y,x)->setVisible(true); getTile(y,x)->setDiscovered(true); return false; } else if (!steep && getTile(x,y)->isBlocked()) { getTile(x,y)->setVisible(true); getTile(x,y)->setDiscovered(true); return false; } error -= deltay; if (error < 0) { y = y + ystep; error = error + deltax; } } return true; } If anyone could help me make the first blocked tiles visible but stops the rest, I would appreciate it. thanks, Manderin87

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  • C#. Whats the fastest way to make an integer positive

    - by maxima120
    I asked wrong question previously and was swamped with negative votes... Let me try again... What is absolutely fastest way to make an int positive (given 50/50 distribution of pos/neg over time). To be nominated for an answer I will require MSIL analysis and not a guess or measuring of time with granny's watch... P.S. as one of variations I proposed i * i not because I wanted to do Sqrt(i * i) afterwards but because i will be used only once to be compared to a const. And if i * i will win competition I simply multiply the const.. Hence the following solution is valid: int trigger = realTrigger * realTrigger; i = SomeCalcs(); i = i * i; if(i < trigger) DoSomething(); P.P.S. pointless rant is not acceptable.. like: why do you need this, its BS! C# cannot tolerate developers like you!

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  • linux/shell: change a file's modify timestamp relatively?

    - by index
    My Canon camera produces files like IMG_1234.JPG and MVI_1234.AVI. It also timestamps those files. Unfortunately during a trip to another timezone several cameras were used, one of which did not have the correct time zone set - meta data mess.. Now I would like to correct this. Proposed algorithm: 1 read file's modify date 2 add delta, i.e. hhmmss (preferred: change timezone) 3 write new timestamp Unless someone knows a tool or a combination of tools that do the trick directly, maybe one could simplify the calculation using epoch time (seconds since ..) and whip up a shell script. Any help appreciated!

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  • I'm really offtopic. But I've got a really good reason.

    - by lost
    Is there anyway Encryption on an unidentified file can be broken(file in question: config file and log files from ardamax keylogger). These files date back all the way to 2008. I searched everywhere, nothing on slashdot, nothing on google. Ardamax Keyviewer? Should I just write to Ardamax? I am at a loss of what to do. I feel comprimised. Anyone managed to decrpyt files with Crypto-analysis?

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  • ublas::bounded_vector<> being resized?

    - by n2liquid
    Now, seriously... I'll refrain from using bad words here because we're talking about the Boost fellows. It MUST be my mistake to see things this way, but I can't understand why, so I'll ask it here; maybe someone can enlighten me in this matter. Here it goes: uBLAS has this nice class template called bounded_vector<> that's used to create fixed-size vectors (or so I thought). From the Effective uBLAS wiki (http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?Effective_UBLAS): The default uBLAS vector and matrix types are of variable size. Many linear algebra problems involve vectors with fixed size. 2 and 3 elements are common in geometry! Fixed size storage (akin to C arrays) can be implemented efficiently as it does not involve the overheads (heap management) associated with dynamic storage. uBLAS implements fixed sizes by changing the underling storage of a vector/matrix to a "bounded_array" from the default "unbounded_array". Alright, this bounded_vector<> thing is used to free you from specifying the underlying storage of the vector to a bounded_array<> of the specified size. Here I ask you: doesn't it look like this bounded vector thing has fixed size to you? Well, it doesn't have. At first I felt betrayed by the wiki, but then I reconsidered the meaning of "bounded" and I think I can let it pass. But in case you, like me (I'm still uncertain), is still wondering if this makes sense, what I found out is that the bounded_vector<> actually can be resized, it may only not be greater than the size specified as template parameter. So, first off, do you think they've had a good reason not to make a real fixed<< size vector or matrix type? Do you think it's okay to "sell" this bounded -- as opposed to fixed-size -- vector to the users of my library as a "fixed-size" vector replacement, even named "Vector3" or "Vector2", like the Effective uBLAS wiki did? Do you think I should somehow implement a vector with fixed size for this purpose? If so, how? (Sorry, but I'm really new to uBLAS; just tried it today) I am developing a 3D game. Should uBLAS be used for the calculations involved in this ("hey, geometry!", per Effective uBLAS wiki)? What replacement would you suggest, if not? -- edit And just in case, yes, I've read this warning: It should be noted that this only changes the storage uBLAS uses for the vector3. uBLAS will still use all the same algorithm (which assume a variable size) to manipulate the vector3. In practice this seems to have no negative impact on speed. The above runs just as quickly as a hand crafted vector3 which does not use uBLAS. The only negative impact is that the vector3 always store a "size" member which in this case is redundant [or isn't it? I mean......]. I see it uses the same algorithm, assuming a variable size, but if an operation were to actually change its size, shouldn't it be stopped (assertion)? ublas::bounded_vector<float,3> v3; ublas::bounded_vector<float,2> v2; v3 = v2; std::cout << v3.size() << '\n'; // prints 2 Oh, come on, isn't this just plain betrayal?

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  • Reshape linux md raid5 that is already being reshaped?

    - by smammy
    I just converted my RAID1 array to a RAID5 array and added a third disk to it. I'd like to add a fourth disk without waiting fourteen hours for the first reshape to complete. I just did this: mdadm /dev/md0 --add /dev/sdf1 mdadm --grow /dev/md0 --raid-devices=3 --backup-file=/root/md0_n3.bak The entry in /proc/mdstat looks like this: md0 : active raid5 sdf1[2] sda1[0] sdb1[1] 976759936 blocks super 0.91 level 5, 64k chunk, algorithm 2 [3/3] [UUU] [>....................] reshape = 1.8% (18162944/976759936) finish=834.3min speed=19132K/sec Now I'd like to do this: mdadm /dev/md0 --add /dev/sdd1 mdadm --grow /dev/md0 --raid-devices=4 --backup-file=/root/md8_n4.bak Is this safe, or do I have to wait for the first reshape operation to complete? P.S.: I know I should have added both disks first, and then reshaped from 2 to 4 devices, but it's a little late for that.

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  • Android Image Problem and threshold

    - by Danny_E
    Hey Guys, Long time reader never posted until now. Im having some trouble with Android, im implementing a library called JJIL its an open source imaging library. My problem is this i need to run some analysis on an image and to do so i need to have it in jjil.core.image format and once those processes are complete i need to convert the changed image from jjil.core.image to java.awt.image. I cant seem to find a method of doing this does anyone have any ideas or have any experience with this? I would be grateful of any help. Danny

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  • How to improve workflow for creating a Lua-based Wireshark dissector

    - by piyo
    I've finally created a Dissector for my UDP protocol in Lua for Wireshark, but the work flow is just horrendous. It consists of editing my custom Lua file in my editor, then double-clicking my example capture file to launch Wireshark to see the changes. If there was an error, Wireshark informs me via dialogs or a red line in the Tree analysis sub-pane. I then re-edit my custom Lua file and then close that Wireshark instance, then double-click my example capture file again. It's like compiling a C file and only seeing one compiler error at a time. Is there a better (faster) way of looking at my changes, without having to restart Wireshark all the time? At the time, I was using Wireshark 1.2.9 for Windows with Lua enabled.

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  • How to name an event handler of a private variable in Vb.Net following FxCop rules and Vb.Net standa

    - by SoMoS
    Hello, On one side, in Vb.Net when you add an event handler to an object the created method is named: <NameOfTheObject>_<NameOfTheMethod>. As I like to have consistent syntax I always follow this rule when creating event handlers by hand. On the other side when I create private variables I prefix them with m_ as this is a common thing used by the community, in C# people use to put _ at the beginning of a variable but this is no CLS compliant. At the end, when I create event handlers for events raised by private variables I end with Subs like m_myVariable_MyEvent. Code Analysis (Fx Cop) is complainig about this way of naming because the method does not start with uppercase and because the _, so the question is: What naming standards do you follow when creating event handlers by hand that follow the Fxcop rules if any? Thanks in advance.

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  • Changing encryption settings for Microsoft Office 2010/2013

    - by iridescent
    Although there are Office 2013 settings to change how encryption is performed, when you encrypt Open XML Format files (.docx, .xslx, .pptx, and so on) the default values — AES (Advanced Encryption Standard), 128-bit key length, SHA1, and CBC (cipher block chaining) — provide strong encryption and should be fine for most organizations. Quoted from http://technet.microsoft.com/en-us/library/cc179125.aspx . I can't figure out where is the setting to change how encryption is performed. Is there any possible to change the encryption algorithm being used instead of the default AES-128 ? Thanks.

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  • if there are multiple kernel module can drive the same device, what is the rule to choose from them?

    - by Dyno Fu
    both pcnet32 and vmxnet can drive the device. $ lspci -k ... 02:01.0 Ethernet controller: Advanced Micro Devices [AMD] 79c970 [PCnet32 LANCE] (rev 10) Subsystem: Advanced Micro Devices [AMD] 79c970 [PCnet32 LANCE] Flags: bus master, medium devsel, latency 64, IRQ 19 I/O ports at 2000 [size=128] [virtual] Expansion ROM at dc400000 [disabled] [size=64K] Kernel driver in use: vmxnet Kernel modules: vmxnet, pcnet32 both kernel modules are loaded, $ lsmod | grep net pcnet32 32644 0 vmxnet 17696 0 mii 5212 1 pcnet32 as you see, kernel driver in use is vmxnet. is there any policy/algorithm in kernel how to choose from the candidates?

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  • Excel - check if row contains ANY value *more than once*

    - by user2536778
    I am doing data analysis and sometimes I need to check and to make sure each row in excel does not have any repeated value. I hope that there is a formula where each time if there's a repeated value in the same row, the value will be highlighted and it doesn't matter what value it is, as long as it's repeated in the same row. I try to search it everywhere but the closest I can find is below question & answer ( which couldn't apply to me as I need a formula that can highlight any value that's repeated and not only zero): I have rows which contain grades for students (numerical values), where the number 0 means they missed a class. I want the row to be highlighted in one color if they have "0" 3 or 4 times, and in another color if they have "0" 5 times or more. =COUNTIF(1:1,0)=5 Anyone can help me? Thanks in advance!

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  • Solving a SQL Server Deadlock situation

    - by mjh41
    I am trying to find a solution that will resolve a recurring deadlock situation in SQL server. I have done some analysis on the deadlock graph generated by the profiler trace and have come up with this information: The first process (spid 58) is running this query: UPDATE cds.dbo.task_core SET nstate = 1 WHERE nmboxid = 89 AND ndrawerid = 1 AND nobjectid IN (SELECT nobjectid FROM ( SELECT nobjectid, count(nobjectid) AS counting FROM cds.dbo.task_core GROUP BY nobjectid) task_groups WHERE task_groups.counting > 1) The second process (spid 86) is running this query: INSERT INTO task_core (…) VALUES (…) spid 58 is waiting for a Shared Page lock on CDS.dbo.task_core (spid 86 holds a conflicting intent exclusive (IX) lock) spid 86 is waiting for an Intent Exclusive (IX) page lock on CDS.dbo.task_core (spid 58 holds a conflicting Update lock)

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  • Java: Best practices for turning foreign horror-code into clean API...?

    - by java.is.for.desktop
    Hello, everyone! I have a project (related to graph algorithms). It is written by someone else. The code is horrible: public fields, no getters/setters huge methods, all public some classes have over 20 fields some classes have over 5 constructors (which are also huge) some of those constructors just left many fields null (so I can't make some fields final, because then every second constructor signals errors) methods and classes rely on each other in both directions I have to rewrite this into a clean and understandable API. Problem is: I myself don't understand anything in this code. Please give me hints on analyzing and understanding such code. I was thinking, perhaps, there are tools which perform static code analysis and give me call graphs and things like this.

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  • Better way to make a bash script self-tracing?

    - by Kevin Little
    I have certain critical bash scripts that are invoked by code I don't control, and where I can't see their console output. I want a complete trace of what these scripts did for later analysis. To do this I want to make each script self-tracing. Here is what I am currently doing: #!/bin/bash # if last arg is not '_worker_', relaunch with stdout and stderr # redirected to my log file... if [[ "$BASH_ARGV" != "_worker_" ]]; then $0 "$@" _worker_ >>/some_log_file 2>&1 # add tee if console output wanted exit $? fi # rest of script follows... Is there a better, cleaner way to do this?

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  • MDX: How To Aggregate Hierarchy Level Members With Same Name

    - by Dave Frautnick
    Greetings, I am new to MDX, and am having trouble understanding how to perform an aggregation on a hierarchy level with members that have the same names. This query is particular to Microsoft Analysis Services 2000 cubes. I have a given hierarchy dimension with levels defined as follows: [Segment].[Flow].[Segment Week] Within the [Segment Week] level, I have the following members: [Week- 1] [Week- 2] [Week- 3] ... [Week- 1] [Week- 2] [Week- 3] The members have the same names, but are aligned with a different [Flow] in the parent level. So, the first occurrence of the [Week- 1] member aligns with [Flow].[A] while the second occurrence of [Week- 1] aligns with [Flow].[B]. What I am trying to do is aggregate all the members within the [Segment Week] level that have the same name. In SQL terms, I want to GROUP BY the member names within the [Segment Week] level. I am unsure how to do this. Thank you. Dave

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  • linux/shell: change a file's modify timestamp relatively?

    - by index
    My Canon camera produces files like IMG_1234.JPG and MVI_1234.AVI. It also timestamps those files. Unfortunately during a trip to another timezone several cameras were used, one of which did not have the correct time zone set - meta data mess.. Now I would like to correct this (not EXIF, the file's "modify" timestamp on disk). Proposed algorithm: 1 read file's modify date 2 add delta, i.e. hhmmss (preferred: change timezone) 3 write new timestamp Unless someone knows a tool or a combination of tools that do the trick directly, maybe one could simplify the calculation using epoch time (seconds since ..) and whip up a shell script. Any help appreciated!

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  • Python: how to run several scripts (or functions) at the same time under windows 7 multicore processor 64bit

    - by Gianni
    sorry for this question because there are several examples in Stackoverflow. I am writing in order to clarify some of my doubts because I am quite new in Python language. i wrote a function: def clipmyfile(inFile,poly,outFile): ... # doing something with inFile and poly and return outFile Normally I do this: clipmyfile(inFile="File1.txt",poly="poly1.shp",outFile="res1.txt") clipmyfile(inFile="File2.txt",poly="poly2.shp",outFile="res2.txt") clipmyfile(inFile="File3.txt",poly="poly3.shp",outFile="res3.txt") ...... clipmyfile(inFile="File21.txt",poly="poly21.shp",outFile="res21.txt") I had read in this example Run several python programs at the same time and i can use (but probably i wrong) from multiprocessing import Pool p = Pool(21) # like in your example, running 21 separate processes to run the function in the same time and speed my analysis I am really honest to say that I didn't understand the next step. Thanks in advance for help and suggestion Gianni

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  • Merge overlapping date intervals

    - by leoinfo
    Is there a better way of merging overlapping date intervals? The solution I came up with is so simple that now I wonder if someone else has a better idea of how this could be done. /***** DATA EXAMPLE *****/ DECLARE @T TABLE (d1 DATETIME, d2 DATETIME) INSERT INTO @T (d1, d2) SELECT '2010-01-01','2010-03-31' UNION SELECT '2010-04-01','2010-05-31' UNION SELECT '2010-06-15','2010-06-25' UNION SELECT '2010-06-26','2010-07-10' UNION SELECT '2010-08-01','2010-08-05' UNION SELECT '2010-08-01','2010-08-09' UNION SELECT '2010-08-02','2010-08-07' UNION SELECT '2010-08-08','2010-08-08' UNION SELECT '2010-08-09','2010-08-12' UNION SELECT '2010-07-04','2010-08-16' UNION SELECT '2010-11-01','2010-12-31' UNION SELECT '2010-03-01','2010-06-13' /***** INTERVAL ANALYSIS *****/ WHILE (1=1) BEGIN UPDATE t1 SET t1.d2 = t2.d2 FROM @T AS t1 INNER JOIN @T AS t2 ON DATEADD(day, 1, t1.d2) BETWEEN t2.d1 AND t2.d2 -- AND t1.d2 <= t2.d2 /***** this condition is useless *****/ IF @@ROWCOUNT = 0 BREAK END /***** RESULT *****/ SELECT StartDate = MIN(d1) , EndDate = d2 FROM @T GROUP BY d2 ORDER BY StartDate, EndDate /***** OUTPUT *****/ /***** StartDate EndDate 2010-01-01 2010-06-13 2010-06-15 2010-08-16 2010-11-01 2010-12-31 *****/ EDIT: I realized that the t1.d2 <= t2.d2 condition is not really useful.

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  • What is the best Java numerical method package?

    - by Bob Cross
    I am looking for a Java-based numerical method package that provides functionality including: Solving systems of equations using different numerical analysis algorithms. Matrix methods (e.g., inversion). Spline approximations. Probability distributions and statistical methods. In this case, "best" is defined as a package with a mature and usable API, solid performance and numerical accuracy. Edit: derick van brought up a good point in that cost is a factor. I am heavily biased in favor of free packages but others may have a different emphasis.

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  • How does one modify the thread scheduling behavior when using Threading Building Blocks (TBB)?

    - by J Teller
    Does anyone know how to modify the thread scheduling (specifically affinity) when using TBB? Doing a high level analysis on a simple parallel-for application, it seems like TBB is specifying the underlying threads' affinity in a way that reduces performance. Specifically, the cores I'm running on have hyper-threading enabled, and it looks like TBB is affinitizing threads to the same core even if there is a different core left completely unloaded. FWIW, I realize it's likely that TBB is doing the "right thing" and that changing the threads' affinity will only reduce performance. I'd just like to experiment with it to see if that's really the case.

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  • Reducing time in C# Forms Control.set_Text(string) function

    - by awshepard
    Hoping for a quick answer (which SO seems to be pretty good for)... I just ran a performance analysis with VS2010 on my app, and it turns out that I'm spending about 20% of my time in the Control.set_Text(string) function, as I'm updating labels in quite a few places in my app. The window has a timer object (Forms timer, not Threading timer) that has a timer1_Tick callback, which updates one label every tick (to give a stop-watch sort of effect), and updates about 15 labels once each second. Does anyone have quick suggestions for how to reduce the amount of time spent updating text on a form, other than increasing the update interval? Are there other structures or functions I should be using?

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  • Reference-counted object is used after it is released

    - by EndyVelvet
    Doing code analysis of the project and get the message "Reference-counted object is used after it is released" on the line [defaults setObject: deviceUuid forKey: @ "deviceUuid"]; I watched this topic Obj-C, Reference-counted object is used after it is released? But the solution is not found. ARC disabled. // Get the users Device Model, Display Name, Unique ID, Token & Version Number UIDevice *dev = [UIDevice currentDevice]; NSString *deviceUuid; if ([dev respondsToSelector:@selector(uniqueIdentifier)]) deviceUuid = dev.uniqueIdentifier; else { NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; id uuid = [defaults objectForKey:@"deviceUuid"]; if (uuid) deviceUuid = (NSString *)uuid; else { CFStringRef cfUuid = CFUUIDCreateString(NULL, CFUUIDCreate(NULL)); deviceUuid = (NSString *)cfUuid; CFRelease(cfUuid); [defaults setObject:deviceUuid forKey:@"deviceUuid"]; } } Please help find the cause.

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