Search Results

Search found 2156 results on 87 pages for 'weighted average'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 3/87 | < Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >

  • Number of malicious attacks defended/done on the average user daily [closed]

    - by DalexL
    As a web hoster, it is very easy to notice the large amounts of exploit/abuse attempts done on my servers. Out of curiosity, how often are these attempts done on the average user? I'm assuming almost all of them are prevented just by simple security protocols in place by their browsers, local network, etc. How many attempts, on average, are committed against a single user daily through any method? (email, internet, downloads, etc.)? If known, what percentage of these things are blocked by the average users security? I tried googling but I was having a hard time getting the right search terms together.

    Read the article

  • Strategy to store/average logs of pings

    - by José Tomás Tocino
    I'm developing a site to monitor web services. The most basic type of check is sending a ping, storing the response time in a CheckLog object. By default, PingCheck objects are triggered every minute, so in one hour you get 60 CheckLogs and in one day you get 1440 CheckLogs. That's a lot of them, I don't need to store such level of detail, so I've set a up collapsing mechanism that periodically takes the uncollapsed CheckLogs older than 24h and collapses (averages) them in intervals of 30 minutes. So, if you have 360 CheckLogs that have been saved from 0:00 to 6:00, after collapsing you retain just 12 of them. The problem.. well, is this: After averaging the response times, the graph changes drastically. What can I do to improve this? Guess one option could be narrowing the interval duration to 15 min. I've seen the graphs at the GitHub status page and they do not seem to suffer from this problem. I'd appreciate any kind of information you could give me about this area.

    Read the article

  • python, wrapping class returning the average of the wrapped members

    - by João Portela
    The title isn't very clear but I'll try to explain. Having this class: class Wrapped(object): def method_a(self): # do some operations return n def method_b(self): # also do some operations return n I wan't to have a class that performs the same way as this one: class Wrapper(object): def __init__(self): self.ws = [Wrapped(1),Wrapped(2),Wrapped(3)] def method_a(self): results=[Wrapped.method_a(w) for w in self.ws] sum_ = sum(results,0.0) average = sum_/len(self.ws) return average def method_b(self): results=[Wrapped.method_b(w) for w in self.ws] sum_ = sum(results,0.0) average = sum_/len(self.ws) return average obviously this is not the actual problem at hand (it is not only two methods), and this code is also incomplete (only included the minimum to explain the problem). So, what i am looking for is a way to obtain this behavior. Meaning, whichever method is called in the wrapper class, call that method for all the Wrapped class objects and return the average of their results. Can it be done? how? Thanks in advance. ps-didn't know which tags to include...

    Read the article

  • Estimate gaussian (mixture) density from a set of weighted samples

    - by Christian
    Assume I have a set of weighted samples, where each samples has a corresponding weight between 0 and 1. I'd like to estimate the parameters of a gaussian mixture distribution that is biased towards the samples with higher weight. In the usual non-weighted case gaussian mixture estimation is done via the EM algorithm. Does anyone know an implementation (any language is ok) that permits passing weights? If not, does anyone know how to modify the algorithm to account for the weights? If not, can some one give me a hint on how to incorporate the weights in the initial formula of the maximum-log-likelihood formulation of the problem? Thanks!

    Read the article

  • postgresql weighted average?

    - by milovanderlinden
    say I have a postgresql table with the following values: id | value ---------- 1 | 4 2 | 8 3 | 100 4 | 5 5 | 7 If I use postgresql to calculate the average, it gives me an average of 24.8 because the high value of 100 has great impact on the calculation. While in fact I would like to find an average somewhere around 6 and eliminate the extreme(s). I am looking for a way to eliminate extremes and want to do this "statistically correct". The extreme's cannot be fixed. I cannot say; If a value is over X, it has to be eliminated. I have been bending my head on the postgresql aggregate functions but cannot put my finger on what is right for me to use. Any suggestions?

    Read the article

  • Find the centroid of a polygon with weighted vertices

    - by Calle Kabo
    Hi, I know how to find the centroid (center of mass) of a regular polygon. This assumes that every part of the polygon weighs the same. But how do I calculate the centroid of a weightless polygon (made from aerogel perhaps :), where each vertex has a weight? Simplified illustration of what I mean using straight line: 5kg-----------------5kg ^center of gravity 10kg---------------5kg ^center of gravity offset du to weight of vertices Of course, I know how to calculate the center of gravity on a straight line with weighted vertices, but how do I do it on a polygon with weighted vertices? Thanks for your time!

    Read the article

  • Weighted round robins via TTL - possible?

    - by Joe Hopfgartner
    I currently use DNS round robin for load balancing, which works great. The records look like this (I have a ttl of 120 seconds) ;; ANSWER SECTION: orion.2x.to. 116 IN A 80.237.201.41 orion.2x.to. 116 IN A 87.230.54.12 orion.2x.to. 116 IN A 87.230.100.10 orion.2x.to. 116 IN A 87.230.51.65 I learned that not every ISP / device treats such a response the same way. For example some DNS servers rotate the addresses randomly or always cycle them through. Some just propagate the first entry, others try to determine which is best (regionally near) by looking at the ip address. However if the userbase is big enough (spreads over multiple ISPs etc) it balances pretty well. The discrepancies from highest to lowest loaded server hardly every exceeds 15%. However now I have the problem that I am introducing more servers into the systems, that not all have the same capacities. I currently only have 1gbps servers, but I want to work with 100mbit and also 10gbps servers too. So what I want is I want to introduce a server with 10 GBps with a weight of 100, a 1 gbps server with a weight of 10 and a 100 mbit server with a weight of 1. I used to add servers twice to bring more traffic to them (which worked nice. the bandwidth doubled almost.) But adding a 10gbit server 100 times to DNS is a bit rediculous. So I thought about using the TTL. If I give server A 240 seconds ttl and server B only 120 seconds (which is about about the minimum to use for round robin, as a lot of dns servers set to 120 if a lower ttl is specified.. so i have heard) I think something like this should occour in an ideal scenario: first 120 seconds 50% of requests get server A -> keep it for 240 seconds. 50% of requests get server B -> keep it for 120 seconds second 120 seconds 50% of requests still have server A cached -> keep it for another 120 seconds. 25% of requests get server A -> keep it for 240 seconds 25% of requests get server B -> keep it for 120 seconds third 120 seconds 25% will get server A (from the 50% of Server A that now expired) -> cache 240 sec 25% will get server B (from the 50% of Server A that now expired) -> cache 120 sec 25% will have server A cached for another 120 seconds 12.5% will get server B (from the 25% of server B that now expired) -> cache 120sec 12.5% will get server A (from the 25% of server B that now expired) -> cache 240 sec fourth 120 seconds 25% will have server A cached -> cache for another 120 secs 12.5% will get server A (from the 25% of b that now expired) -> cache 240 secs 12.5% will get server B (from the 25% of b that now expired) -> cache 120 secs 12.5% will get server A (from the 25% of a that now expired) -> cache 240 secs 12.5% will get server B (from the 25% of a that now expired) -> cache 120 secs 6.25% will get server A (from the 12.5% of b that now expired) -> cache 240 secs 6.25% will get server B (from the 12.5% of b that now expired) -> cache 120 secs 12.5% will have server A cached -> cache another 120 secs ... i think i lost something at this point but i think you get the idea.... As you can see this gets pretty complicated to predict and it will for sure not work out like this in practice. But it should definitely have an effect on the distribution! I know that weighted round robin exists and is just controlled by the root server. It just cycles through dns records when responding and returns dns records with a set propability that corresponds to the weighting. My DNS server does not support this, and my requirements are not that precise. If it doesnt weight perfectly its okay, but it should go into the right direction. I think using the TTL field could be a more elegant and easier solution - and it deosnt require a dns server that controls this dynamically, which saves resources - which is in my opinion the whole point of dns load balancing vs hardware load balancers. My question now is... are there any best prectices / methos / rules of thumb to weight round robin distribution using the TTL attribute of DNS records? Edit: The system is a forward proxy server system. The amount of Bandwidth (not requests) exceeds what one single server with ethernet can handle. So I need a balancing solution that distributes the bandwidth to several servers. Are there any alternative methods than using DNS? Of course I can use a load balancer with fibre channel etc, but the costs are rediciulous and it also increases only the width of the bottleneck and does not eliminate it. The only thing i can think of are anycast (is it anycast or multicast?) ip addresses, but I don't have the means to set up such a system.

    Read the article

  • How is load average related to CPU utilization?

    - by Kaustubh P
    I am facing a load average of 3 since past 2 days. The CPU utilization is never above 40 % in all cases. Here are some screenshots of Server Density monitoring tool that I use. The process snapshot at the highest peak, @ 0:00 is as follows: And the process snapshot at the peak created at 12:00 is: My question is, even though CPU utilization is not 100 %, why am I facing a high average? PS: All snapshots are sorted by descending CPU utilization.

    Read the article

  • Calculate average gas prices by year in excel

    - by ghostryder111
    I have 3 columns, A=Date, B=Price, C=Grade in Excel. I want to calculate the average price of fuel for each year and an overall average of all years by grade. The data table looks like this Date | Price | Grade 2012-05-01 | $3.49 | Regular 2012-06-07 | $3.58 | Regular 2012-04-01 | $3.98 | Premium 2012-02-17 | $3.87 | Premium 2013-01-01 | $3.49 | Regular 2013-02-01 | $3.89 | Premium 2013-03-06 | $3.89 | Premium 2013-03-09 | $3.45 | Regular The output should look something like this: Year | Regular | Premium 2012 | 3.43 | 3.67 2013 | 3.45 | 3.73 All | 3.44 | 3.70

    Read the article

  • No apparent reason for high load average

    - by Oz.
    We have several web servers running on Amazon (ec2) c1.xlarge, over Amazon AMI. The servers are duplicates of each other, running the exact same hardware and software. Each server spec is: 7 GB of memory 20 EC2 Compute Units (8 virtual cores with 2.5 EC2 Compute Units each) 1690 GB of instance storage 64-bit platform I/O Performance: High API name: c1.xlarge A couple of weeks ago we have run a yum upgrade on one of the servers. Starting on this upgrade the upgraded server started showing a high load average. Needless to say, we did not update the other servers and we can not do so until we understand the reason for this behavior. The strange thing is that when we compare the servers using top or iostat, we can not find the reason for the high load. Note that we have moved traffic from the "problematic" server to the others, which have made the "problematic" server less crowded in terms of requests, and still his load is higher. Do you have any idea what could it be, or where else can we check? Many thanks for the help! Oz. # # proper server # w command # 00:42:26 up 2 days, 19:54, 2 users, load average: 0.41, 0.48, 0.49 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT pts/1 82.80.137.29 00:28 14:05 0.01s 0.01s -bash pts/2 82.80.137.29 00:38 0.00s 0.02s 0.00s w # # proper server # iostat command # Linux 3.2.12-3.2.4.amzn1.x86_64 _x86_64_ (8 CPU) avg-cpu: %user %nice %system %iowait %steal %idle 9.03 0.02 4.26 0.17 0.13 86.39 Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn xvdap1 1.63 1.50 55.00 367236 13444008 xvdfp1 4.41 45.93 70.48 11227226 17228552 xvdfp2 2.61 2.01 59.81 491890 14620104 xvdfp3 8.16 14.47 94.23 3536522 23034376 xvdfp4 0.98 0.79 45.86 192818 11209784 # # problematic server # w command # 00:43:26 up 2 days, 21:52, 2 users, load average: 1.35, 1.10, 1.17 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT pts/0 82.80.137.29 00:28 15:04 0.02s 0.02s -bash pts/1 82.80.137.29 00:38 0.00s 0.05s 0.00s w # # problematic server # iostat command # Linux 3.2.20-1.29.6.amzn1.x86_64 _x86_64_ (8 CPU) avg-cpu: %user %nice %system %iowait %steal %idle 7.97 0.04 3.43 0.19 0.07 88.30 Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn xvdap1 2.10 1.49 76.54 374660 19253592 xvdfp1 5.64 40.98 85.92 10308946 21612112 xvdfp2 3.97 4.32 93.18 1087090 23439488 xvdfp3 10.87 30.30 115.14 7622474 28961720 xvdfp4 1.12 0.28 65.54 71034 16487112

    Read the article

  • Compute average distance from point to line segment and line segment to line segment

    - by Fred
    Hi everyone, I'm searching for an algorithm to calculate the average distance between a point and a line segment in 3D. So given two points A(x1, y1, z1) and B(x2, y2, z2) that represent line segment AB, and a third point C(x3, y3, z3), what is the average distance between each point on AB to point C? I'm also interested in the average distance between two line segments. So given segment AB and CD, what is the average distance from each point on AB to the closest point on CD? I haven't had any luck with the web searches I've tried, so any suggestions would be appreciated. Thanks.

    Read the article

  • Slow Memcached: Average 10ms memcached `get`

    - by Chris W.
    We're using Newrelic to measure our Python/Django application performance. Newrelic is reporting that across our system "Memcached" is taking an average of 12ms to respond to commands. Drilling down into the top dozen or so web views (by # of requests) I can see that some Memcache get take up to 30ms; I can't find a single use of Memcache get that returns in less than 10ms. More details on the system architecture: Currently we have four application servers each of which has a memcached member. All four memcached members participate in a memcache cluster. We're running on a cloud hosting provider and all traffic is running across the "internal" network (via "internal" IPs) When I ping from one application server to another the responses are in ~0.5ms Isn't 10ms a slow response time for Memcached? As far as I understand if you think "Memcache is too slow" then "you're doing it wrong". So am I doing it wrong? Here's the output of the memcache-top command: memcache-top v0.7 (default port: 11211, color: on, refresh: 3 seconds) INSTANCE USAGE HIT % CONN TIME EVICT/s GETS/s SETS/s READ/s WRITE/s cache1:11211 37.1% 62.7% 10 5.3ms 0.0 73 9 3958 84.6K cache2:11211 42.4% 60.8% 11 4.4ms 0.0 46 12 3848 62.2K cache3:11211 37.5% 66.5% 12 4.2ms 0.0 75 17 6056 170.4K AVERAGE: 39.0% 63.3% 11 4.6ms 0.0 64 13 4620 105.7K TOTAL: 0.1GB/ 0.4GB 33 13.9ms 0.0 193 38 13.5K 317.2K (ctrl-c to quit.) ** Here is the output of the top command on one machine: ** (Roughly the same on all cluster machines. As you can see there is very low CPU utilization, because these machines only run memcache.) top - 21:48:56 up 1 day, 4:56, 1 user, load average: 0.01, 0.06, 0.05 Tasks: 70 total, 1 running, 69 sleeping, 0 stopped, 0 zombie Cpu(s): 0.0%us, 0.0%sy, 0.0%ni, 99.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.3%st Mem: 501392k total, 424940k used, 76452k free, 66416k buffers Swap: 499996k total, 13064k used, 486932k free, 181168k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 6519 nobody 20 0 384m 74m 880 S 1.0 15.3 18:22.97 memcached 3 root 20 0 0 0 0 S 0.3 0.0 0:38.03 ksoftirqd/0 1 root 20 0 24332 1552 776 S 0.0 0.3 0:00.56 init 2 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kthreadd 4 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kworker/0:0 5 root 20 0 0 0 0 S 0.0 0.0 0:00.02 kworker/u:0 6 root RT 0 0 0 0 S 0.0 0.0 0:00.00 migration/0 7 root RT 0 0 0 0 S 0.0 0.0 0:00.62 watchdog/0 8 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 cpuset 9 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 khelper ...output truncated...

    Read the article

  • How to get average of multiple time series

    - by Supun Kamburugamuva
    I have few computers running. I want to get the average CPU usage of these computers and plot it as a graph. So I've collected CPU usage in regular intervals in these machines. So for each computer I have a data set of time and CPU usage. But the times at which CPU measurements are taken in different machines are not in sync. For example in 1st machine CPU may be measured in time 1, 5, 9. In the second machine CPU may be measured in time 2, 5, 8. I want to get an average data series from these different data sets. Could you point me to some resources? Thanks - Supun.

    Read the article

  • Calculating the average color between two colors in PHP, using an index number as reference value

    - by Roel Krottje
    Hi all! In PHP, I am trying to calculate the average color (in hex) between to different hex colors.. However, I also need to be able to supply an index number between 0.0 and 1.0. So for example: I have $color1 = "#ffffff" and $color2 = "#0066CC" .. If I would write a function to get the average color and I would supply 0.0 as the index number, the function would need to return "#ffffff". If I would supply 1.0 as the index number, the function would need to return "#0066CC".. However if I would supply 0.2, the function would need to return an average color between the two colors, but still closer to color1 than to color2.. If I would supply index number 0.5, I would get the exact average color of both colors.. I have been trying to accomplish this for several days now but I can't seem to figure it out..! Any help would therefor be greatly appreciated!.. Thanks!

    Read the article

  • Power Pivot - Average time per item

    - by Username
    I'm trying to calculate on average, how long it takes to make each item. Here is the data table: Date Item Quantity Operator 01/01/2014 Item1 3 John 01/01/2014 Item2 5 John 02/01/2014 Item1 7 Bob 02/01/2014 Item2 4 John 03/01/2014 Item1 2 Bob 07/01/2014 Item2 3 John On 01/01/2014 John made 3 of Item 1 and 5 of Item 2. If we only had the first 2 rows we can guess that it takes 0.375 days to make Item 1 and 0.625 days to make Item 2. I want to be able to calculate this on average using all the data and taking in to account the operators obviously working on different items. Thank you

    Read the article

  • mysql/algorithm: Weighting an average to accentuate differences from the mean

    - by Sai Emrys
    This is for a new feature on http://cssfingerprint.com (see /about for general info). The feature looks up the sites you've visited in a database of site demographics, and tries to guess what your demographic stats are based on that. All my demgraphics are in 0..1 probability format, not ratios or absolute numbers or the like. Essentially, you have a large number of data points that each tend you towards their own demographics. However, just taking the average is poor, because it means that by adding in a lot of generic data, the number goes down. For example, suppose you've visited sites S0..S50. All except S0 are 48% female; S0 is 100% male. If I'm guessing your gender, I want to have a value close to 100%, not just the 49% that a straight average would give. Also, consider that most demographics (i.e. everything other than gender) does not have the average at 50%. For example, the average probability of having kids 0-17 is ~37%. The more a given site's demographics are different from this average (e.g. maybe it's a site for parents, or for child-free people), the more it should count in my guess of your status. What's the best way to calculate this? For extra credit: what's the best way to calculate this, that is also cheap & easy to do in mysql?

    Read the article

  • MySQL: Get average of time differences?

    - by Nebs
    I have a table called Sessions with two datetime columns: start and end. For each day (YYYY-MM-DD) there can be many different start and end times (HH:ii:ss). I need to find a daily average of all the differences between these start and end times. An example of a few rows would be: start: 2010-04-10 12:30:00 end: 2010-04-10 12:30:50 start: 2010-04-10 13:20:00 end: 2010-04-10 13:21:00 start: 2010-04-10 14:10:00 end: 2010-04-10 14:15:00 start: 2010-04-10 15:45:00 end: 2010-04-10 15:45:05 start: 2010-05-10 09:12:00 end: 2010-05-10 09:13:12 ... The time differences (in seconds) for 2010-04-10 would be: 50 60 300 5 The average for 2010-04-10 would be 103.75 seconds. I would like my query to return something like: day: 2010-04-10 ave: 103.75 day: 2010-05-10 ave: 72 ... I can get the time difference grouped by start date but I'm not sure how to get the average. I tried using the AVG function but I think it only works directly on column values (rather than the result of another aggregate function). This is what I have: SELECT TIME_TO_SEC(TIMEDIFF(end,start)) AS timediff FROM Sessions GROUP BY DATE(start) Is there a way to get the average of timediff for each start date group? I'm new to aggregate functions so maybe I'm misunderstanding something. If you know of an alternate solution please share. I could always do it ad hoc and compute the average manually in PHP but I'm wondering if there's a way to do it in MySQL so I can avoid running a bunch of loops. Thanks.

    Read the article

  • Finding the average of two number using classes and methods

    - by Have alook
    I want to use methods inside class. Q: find the average of two number using classes and methods. import java.util.*; class aaa { int a,b,sum,avrg; void average() { System.out.println("The average is ="+avrg); avrg=(sum/2); } } class ave { public static void main(String args[]){ aaa n=new aaa(); Scanner m=new Scanner(System.in); System.out.println("write two number"); n.a=m.nextInt(); n.b=m.nextInt(); n.average(); } }

    Read the article

  • Storm Trident 'average aggregator

    - by E Shindler
    I am a newbie to Trident and I'm looking to create an 'Average' aggregator similar to 'Sum(), but for 'Average'.The following does not work: public class Average implements CombinerAggregator<Long>.......{ public Long init(TridentTuple tuple) { (Long)tuple.getValue(0); } public Long Combine(long val1,long val2){ return val1+val2/2; } public Long zero(){ return 0L; } } It may not be exactly syntactically correct, but that's the idea. Please help if you can. Given 2 tuples with values [2,4,1] and [2,2,5] and fields 'a','b' and 'c' and doing an average on field 'b' should return '3'. I'm not entirely sure how init() and zero() work. Thank you so much for your help in advance. Eli

    Read the article

  • Linq Query - Average Time (DateTime data types)

    - by Jade
    I have a database that has the following records in a DateTime field: 2012-04-13 08:31:00.000 2012-04-12 07:53:00.000 2012-04-11 07:59:00.000 2012-04-10 08:16:00.000 2012-04-09 15:11:00.000 2012-04-08 08:28:00.000 2012-04-06 08:26:00.000 I want to run a linq to sql query to get the average time from the records above. I tried the following: (From o In MYDATA Select o.SleepTo).Average() Since "SleepTo" is a datetime field I get an error on Average(). If I was trying to get the average of say an integer, the above linq query works. What do I need to do to get it to work for datetimes?

    Read the article

  • c++ programming- Tryin to get a number within an array that is twice the average

    - by max
    i have been assigned to set up an array with points. I am told to get the maximum value, average, nd within this same array, if any point in the array is twice the average, i should cout an "outlier." So far i have gotten the average and maximum numbers in the array. but i am unable to set the programme to cout the outlier. Instead it gives me a multiple of the average. pls help! here is the programme; int main() { const int max = 10; int ary[max]={4, 32, 9, 7, 14, 12, 13, 17, 19, 18}; int i,maxv; double out,sum=0; double av; maxv= ary[0]; for(i=0; i } cout<<"maximum value: "< for(i=0; i sum = sum + ary[i]; av = sum / max; } cout<<"average: "< out = av * 2; if(ary[i]out) { cout<<"outlier: "< return 0; }

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >