I'm trying to figure out if there is a correct way to set the Stop Loss (SL) and Take Profit (TP) levels, when sending an order in an Expert Advisor, in MQL4 (Metatrader4). The functional template is:
OrderSend( symbol, cmd, volume, price, slippage, stoploss, takeprofit, comment, magic, expiration, arrow_color);
So naturally I've tried to do the following:
double dSL = Point*MM_SL;
double dTP = Point*MM_TP;
if (buy) { cmd = OP_BUY; price = Ask; SL = ND(Bid - dSL); TP = ND(Ask + dTP); }
if (sell) { cmd = OP_SELL; price = Bid; SL = ND(Ask + dSL); TP = ND(Bid - dTP); }
ticket = OrderSend(SYM, cmd, LOTS, price, SLIP, SL, TP, comment, magic, 0, Blue);
However, there are as many variations as there are scripts and EA's. So far I have come across these.
In the MQL4 Reference in the MetaEditor, the documentation say to use:
OrderSend(Symbol(),OP_BUY,Lots,Ask,3,
NormalizeDouble(Bid - StopLoss*Point,Digits),
NormalizeDouble(Ask + TakeProfit*Point,Digits),
"My order #2",3,D'2005.10.10 12:30',Red);
While in the "same" documentation online, they use:
double stoploss = NormalizeDouble(Bid - minstoplevel*Point,Digits);
double takeprofit = NormalizeDouble(Bid + minstoplevel*Point,Digits);
int ticket=OrderSend(Symbol(),OP_BUY,1,price,3,stoploss,takeprofit,"My order",16384,0,clrGreen);
And so it goes on with various flavors, here, here and here...
Assuming we are interested in a OP_BUY and have the signs correct, we have the options for basing our SL and TP values on:
bid, bid
bid, ask
ask, ask
ask, bid
So what is the correct way to set the SL and TP for a BUY?
(What are the advantages or disadvantages of using the various variations?)
EDIT: 2018-06-12
Apart a few details, the answer is actually quite simple, although not obvious. Perhaps because MT4 only show Bid prices on the chart (by default) and not both Ask and Bid.
So because: Ask > Bid and Ask - Bid = Slippage, it doesn't matter which we choose as long as we know about the slippage. Then depending on what price you are following on the chart, you may wish to decide on using one over the other, adding or subtracting the Slippage accordingly.
So when you use the measure tool to get the Pip difference of currently shown prices, vs your "exact" SL/TP settings, you need to keep this in mind.
So to avoid having to put the Slippage in my code above, I used the following for OP_BUY: TP = ND(Bid + dTP); (and the opposite for OP_SELL.)
If you buy, you OP_BUY at Ask and close (SL, TP) at Bid.
If you sell, OP_SELL operation is made at Bid price, and closes at Ask.
Both SL and TP should stay at least within STOP_LEVEL * Point() distance from the current price to close ( Bid for buy, Ask for sell).
It is possible that STOP_LEVEL is zero - in such cases ( while MT4 accepts the order ) the Broker may reject it, based on its own algorithms ( Terms and Conditions may call it a "floating Stoplevel" rule or some similar Marketing-wise "re-dressed" term ).
It is adviced to send an OrderSend() request with zero values of SL and TP and modify it after you see that the order was sent successfully. Sometimes it is not required, sometimes that is even mandatory.
There is no difference between the two links you gave us: you may compute SL and TP and then pass them into the function or compute them based on OrderOpenPrice() +/- distance * Point().
So what is the correct way to set the SL and TP for a BUY ?
There is no such thing as "The Correct Way", there are rules to meet
Level 0: Syntax is to meet the call-signature ( the easiest one )
Level 1: all at Market XTO-s have to meet the right level of the current Price +/- slippage, make sure to repeat a RefreshRates()-test as close to the PriceDOMAIN-levels settings, otherwise they get rejected from the Broker side ( blocking one's trading engine at a non-deterministic add-on RTT-latency ) + GetLastError() == 129 | ERR_INVALID_PRICE
Level 2: yet another rules get set from Broker-side, in theire respective Service / Product definition in [ Trading Terms and Conditions ]. If one's OrderSend()-request fails to meet any one of these, again, the XTO will get rejected, having same adverse blocking effects, as noted in Level 1.
Some Brokers do not allow some XTO situations due to their T&C, so re-read such conditions with a due care. Any single of theirs rule, if violated, will lead to your XTO-instruction to get legally rejected, with all adverse effects, as noted above. Check all rules, as you will not like to see any of the following error-states + any of others, restricted by your Broker's T&C :
ERR_LONG_POSITIONS_ONLY_ALLOWED Buy orders only allowed
ERR_TRADE_TOO_MANY_ORDERS The amount of open and pending orders has reached the limit set by the broker
ERR_TRADE_HEDGE_PROHIBITED An attempt to open an order opposite to the existing one when hedging is disabled
ERR_TRADE_PROHIBITED_BY_FIFO An attempt to close an order contravening the FIFO rule
ERR_INVALID_STOPS Invalid stops
ERR_INVALID_TRADE_VOLUME Invalid trade volume
...
..
.
#ASSUME NOTHING ; Is the best & safest design-side (self)-directive
I am trying to program a simple Babymonitor for Windows (personal use).
The babymonitor should just detect the dB level of the microphone and triggers at a certain volume.
After some research, I found the Bass.dll library and came across it's function BASS_ChannelGetLevel, which is great but seems to have limitations and doesn't fit my needs (Peak equals to a DWORD value).
In the examples I found a livespec example which is "almost" what I need. The example uses BASS_ChannelGetData, but I don't quite know how to handle the returned array...
I want to keep it as simple as possible: Detect the volume from the microphone as dB or any other value (e.g. value 0-MAXINT).
How can this be done with the Bass.dll library?
The BASS_ChannelGetLevel returns the value that is capped to 0dB (return value is 32768 in this case). If you adjust your source level (lower microphone level in sound card settings) then it will work just fine.
Another way, if you want to get uncapped value is to use the BASS_ChannelGetLevelEx function instead: it returns floating point levels, where 1 is maximum (0dB) value that corresponds to BASS_ChannelGetLevel's 32767, but it can exceed 1 to detect sound levels above 0dB which is what you may need.
I also suggest you to monitor sound level for a while: trigger only if certain level exists for 2-3 seconds at least (this way you will exclude false alarms).
Here is how you obtain the db level given an input stream handle (streamHandle):
var peak = (double)Bass.BASS_ChannelGetLevel(streamHandle);
var decibels = 20 * Math.Log10(peak / Int32.MaxValue);
Alternatively, you can use the following to get the RMS (average) peak. To get the RMS value, you have to pass in a sample length into BASS_ChannelGetLevel. I'm using 20 milliseconds here but you can play with the value to see which works best for your needs.
var decibels = 0m;
var channelCount = 2; //Assuming two channels
var sampleLengthMS = 20f;
var rmsLevels = new float[channelCount];
var rmsObtained = Bass.BASS_ChannelGetLevel(streamHandle, rmsLevels, sampleLengthMS / 1000f, BASSLevel.BASS_LEVEL_RMS);
if (rmsObtained)
decibels = 20*Math.Log10(rmsLevels[0]); //using first channel (index 0) but you can get both if needed.
else
Console.WriteLine(Bass.BASS_ErrorGetCode());
Hope this helps.
I have an assignment where ?I need to take a gross pay that is paid in cash and display how many 100s,50s,20s,10s,5s,1s the employee is paid. I'm sure its just my math that is not working but here is my code
COMPUTE W02-PAY-100S = W02-GROSS-PAY / 100
COMPUTE PAY = W02-GROSS-PAY - (W02-PAY-100S * 100)
COMPUTE W02-PAY-50S = PAY / 50
COMPUTE PAY = PAY - (W02-PAY-50S * 50)
COMPUTE W02-PAY-20S = PAY / 20
COMPUTE PAY = PAY - (W02-PAY-20S * 20)
COMPUTE W02-PAY-10S = PAY / 10
COMPUTE PAY = PAY - (W02-PAY-10S * 10)
COMPUTE W02-PAY-5S = PAY / 5
COMPUTE PAY = PAY - (W02-PAY-5S * 5)
COMPUTE W02-PAY-1S = PAY / 1
.
What ends up happening is the first 100s are displayed as 3, then everything else is 0's.
I'd suspect PAY is defined as PIC 9 rather than PIC 9(7) (or whatever), or that there is some problem with the definitions of the other fields you are using (like no integer parts).
However, you're going about it the "wrong" way for COBOL, by making use of the fact that COMPUTE is like an assignment statement in other languages.
Instead COBOL offers more nuance with verbs for maths. Have a look at DIVIDE with GIVING and REMAINDER.
DIVIDE W02-GROSS-PAY BY 100
GIVING NOTES-100
REMAINDER W-RUNNING-BALANCE-LESS-100S
DIVIDE W-RUNNING-BALANCE-LESS-100S
BY 50
GIVING NOTES-50
REMAINDER W-RUNNING-BALANCE-LESS-50S
DIVIDE W-RUNNING-BALANCE-LESS-50S
BY 20
GIVING NOTES-20
REMAINDER W-RUNNING-BALANCE-LESS-20S
DIVIDE W-RUNNING-BALANCE-LESS-20S
BY 10
GIVING NOTES-10
REMAINDER W-RUNNING-BALANCE-LESS-10S
DIVIDE W-RUNNING-BALANCE-LESS-10S
BY 05
GIVING NOTES-05
REMAINDER COINS-01
If you get your COMPUTEs working, you don't need the last one (divide by one gives you as the answer the original number). With the COMPUTEs you are doing a lot more work than necessary in COBOL.
Now that you know about DIVIDE, also look at MULTIPLY, ADD and SUBTRACT.
To complete the picture, look at the intrinsic functions like INTEGER and MOD. The MOD and more, you have above. The INTEGER is unnecessary because a simple MOVE to a field without a fractional part will get there. A MOVE to a field without an integer part will get you the fraction.
Don't, necessarily, look for something which allows you to do it as you would in another language. You may "pass" your COBOL module that way, but you won't really learn COBOL.
I would like to make sure I have properly adjusted for multiple testing, which I am doing through permutation. I do not want to over-adjust, so I only want to include comparisons that were specified a priori. Here is a dataset that is similar in construction to the one I am analyzing:
data test;
call streaminit(1234);
do a=1 to 5;
do b=1 to 2;
do i = 1 to 8;
censored = rand('BERNOULLI',0.5);
if censored = 0 then ttd = rand('NORMAL',10);
else ttd = 30;
id = 16*(A-1)+8*(B-1)+i;
output;
end;
end;
end;
drop i;
run;
If I were interested in comparing each level of a and b to every other level, I would run the following:
proc lifetest data=test;
time ttd * censored(1);
strata a b / diff=all adjust=simulate(nsamp=1000000 seed=1234);
run;
Instead, I would like to compare each level of a to every other level of a within b (10 comparisons at 2 levels makes 20 comparisons). On top of that, I would like to compare the two levels of b within each level of a (5 comparisons). So in all that is 25 comparisons I have to adjust for, but adjusting for all pairwise comparisons as I have done in the above code accounts for 45 comparisons. Is there a way in proc lifetest to just specify the 25 pairwise comparisons I am interested in? If not, is there some way around this so I can adjust post hoc just for the 25 comparisons I am interested in?
While this is a very statistics-related question, the primary question is about problems specific to programming in SAS and not about which methods to use or the appropriateness of the chosen method, so I am posting it here and not on Cross Validated, though I admit that a post hoc adjustment outside of proc lifetest may be the way to go and so would be willing to let Cross Validated have a shot at it as well.
in fibonacci series let's assume nth fibonacci term is T. F(n)=T. but i want to write a a program that will take T as input and return n that means which term is it in the series( taken that T always will be a fibonacci number. )i want to find if there lies an efficient way to find it.
The easy way would be to simply start generating Fibonacci numbers until F(i) == T, which has a complexity of O(T) if implemented correctly (read: not recursively). This method also allows you to make sure T is a valid Fibonacci number.
If T is guaranteed to be a valid Fibonacci number, you can use approximation rules:
Formula
It looks complicated, but it's not. The point is: from a certain point on, the ratio of F(i+1)/F(i) becomes a constant value. Since we're not generating Fibonacci Numbers but are merely finding the "index", we can drop most of it and just realize the following:
breakpoint := f(T)
Any f(i) where i > T = f(i-1)*Ratio = f(T) * Ratio^(i-T)
We can get the reverse by simply taking Log(N, R), R being Ratio. By adjusting for the inaccuracy for early numbers, we don't even have to select a breakpoint (if you do: it's ~ correct for i > 17).
The Ratio is, approximately, 1.618034. Taking the log(1.618034) of 6765 (= F(20)), we get a value of 18.3277. The accuracy remains the same for any higher Fibonacci numbers, so simply rounding down and adding 2 gives us the exact Fibonacci "rank" (provided that F(1) = F(2) = 1).
The first step is to implement fib numbers in a non-recursive way such as
fib1=0;fib2=1;
for(i=startIndex;i<stopIndex;i++)
{
if(fib1<fib2)
{
fib1+=fib2;
if(fib1=T) return i;
if(fib1>T) return -1;
}
else
{
fib2+=fib1;
if(fib2=T) return i;
if(fib2>t) return -1;
}
}
Here startIndex would be set to 3 stopIndex would be set to 10000 or so. To cut down in the iteration, you can also select 2 seed number that are sequential fib numbers further down the sequence. startIndex is then set to the next index and do the computation with an appropriate adjustment to the stopIndex. I would suggest breaking the sequence up in several section depending on machine performance and the maximum expected input to minimize the run time.