When trying to run the following snippet:
void main() {
double step = 0.1;
double currentAmount = 1;
while (currentAmount < 2) {
currentAmount = currentAmount + step;
print (currentAmount);
}
}
The output is as follows:
1.1
1.2000000000000002
1.3000000000000003
1.4000000000000004
1.5000000000000004
1.6000000000000005
1.7000000000000006
1.8000000000000007
1.9000000000000008
2.000000000000001
Can anybody tell me why the decimals are appearing as such and is this the normal behavior?
That's because you are losing precision
have a look at this package, it should solve your problem
Related
This is my sample provider implementation
public class FilterSampleProvider : ISampleProvider
{
private ISampleProvider sourceProvider;
private float cutOffFreq;
private float bandWidth;
private BiQuadFilter filter;
public FilterSampleProvider(ISampleProvider sourceProvider, int cutOffFreq, int bandWidth)
{
this.sourceProvider = sourceProvider;
this.cutOffFreq = cutOffFreq;
this.bandWidth = bandWidth;
filter = BiQuadFilter.LowPassFilter(sourceProvider.WaveFormat.SampleRate, this.cutOffFreq, this.bandWidth);
}
public WaveFormat WaveFormat { get { return sourceProvider.WaveFormat; } }
public int Read(float[] buffer, int offset, int count)
{
int samplesRead = sourceProvider.Read(buffer, offset, count);
for (int i = 0; i < samplesRead; i++)
buffer[offset + i] = filter.Transform(buffer[offset + i]);
return samplesRead;
}
}
I am generating a sin wave at 4000 hz frequency using the below code
var sine20Seconds = new SignalGenerator()
{
Gain = 1,
Frequency = 4000,
Type = SignalGeneratorType.Sin
}
.Take(TimeSpan.FromSeconds(60));
Then I am creating a file and again reading the file because i want the original file to compare with the output.
WaveFileWriter.CreateWaveFile("filteroutput.wav", sine20Seconds.ToWaveProvider());
var reader = new WaveFileReader(File.OpenRead("filteroutput.wav"));
Then creating my filter sample provider with a cutoff frequency of 500, output I am expecting is a file without the sin wave hum
filterSampleProvider = new FilterSampleProvider(reader.ToSampleProvider(),500,1);
filteredWaveProvider = filterSampleProvider.ToWaveProvider();
I believe the q is for Quality Factor so I am passing 1
WaveFileWriter.CreateWaveFile("filteroutput1.wav", filteredWaveProvider);
Then I am create a new output file.
the output file after going through LFT is still having the sin wave at 4000Hz
Is there anything I am doing wrong?
After going through the Github Code repo of NAudio I am confused about the q value, is it quality factor or bandwidth? why would you have a bandwidth for low pass filter?
So I got a couple of ideas and I'd like to backtest them. And to do so, the indicator must run internally within the EA rather than take its value from the iCustom method. I've got the indicator free from a very nice guy from the internet (obviously...) and I've like to test around with it.
Unfortunately the indicator mentioned is using the OnCalculate function which is only working within indicators and not EAs. So basically copy-pasting code inside EA is really not a option unfortunately.
Didn't provide code as the problem is a simple as I describe it to keep it short. If you believe this would help, I am more than happy to provide that as well.
EDIT. Added indicator code:
int OnCalculate(const int rates_total,
const int prev_calculated,
const datetime &time[],
const double &open[],
const double &high[],
const double &low[],
const double &close[],
const long &tick_volume[],
const long &volume[],
const int &spread[])
{
//---
int startIndex = MathMax(0, rates_total - prev_calculated - 1);
// Only calculate up until the previous bar. We don't want to calculate the current bar.
if (startIndex > 0)
{
for (int i = startIndex; i >= 1; i--)
{
double
ohlcAvg = (open[i] + high[i] + low[i] + close[i])/4,
vol = (double) tick_volume[i];
// Reset values when session changed
if (TimeDay(time[i]) != TimeDay(__sessionStartTime))
{
__sessionStartTime = time[i];
__ohlcvTotal = 0;
__volumeTotal = 0;
}
__ohlcvTotal += ohlcAvg * vol;
__volumeTotal += vol;
ExtBuffer1[i] = NormalizeDouble(__ohlcvTotal/__volumeTotal, _Digits);
}
}
return(rates_total - 1);
}
In most cases you can create a custom function within an EA that replicates an indicator by using buffers. I have done this numerous times for clients as it makes the EA a more robust solution when not relying on external indicators.
Example code:
//+------------------------------------------------------------------+
double customIndicator(int IDX, int timeFrame)
//+------------------------------------------------------------------+
{
double Buffer[1];
int buffersize=iBars(Symbol(), timeFrame);
ArrayResize(Buffer, buffersize);
ArraySetAsSeries(Buffer, true);
int pos=buffersize-1;
while(pos>=0)
{
// Indicator calculations
Buffer[pos]=...
pos--;
}
return(buffer[IDX]);
}
#property strict
string subfolder = "ipc\\";
int last_read = 0;
int t = 0;
struct trade_message
{
int time; // time
string asset; // asset
string direction; // direction
double open_price; // open
double stop_price; // open
double close_price;// open
float fraction; // fraction
string comment; // comment
string status; // status
};
trade_message messages[];
int OnInit()
{
int FH = FileOpen(subfolder+"processedtime.log",FILE_BIN);
if(FH >=0)
{
last_read = FileReadInteger(FH,4);
FileClose(FH);
}
return(INIT_SUCCEEDED);
}
void OnTick()
{
int FH=FileOpen(subfolder+"data.csv",FILE_READ|FILE_CSV, ","); //open file
int p=0;
while(!FileIsEnding(FH))
{
t = StringToInteger(FileReadString(FH));
if(t<=last_read)
{
break;
}
do
{
messages[p].time = t; // time
messages[p].direction = FileReadString(FH); // direction
messages[p].open_price = StringToDouble(FileReadString(FH)); // open
messages[p].stop_price = StringToDouble(FileReadString(FH)); // stop
messages[p].close_price = StringToDouble(FileReadString(FH)); // close
messages[p].fraction = StringToDouble(FileReadString(FH)); // fraction (?float)
messages[p].comment = FileReadString(FH); // comment
messages[p].status = FileReadString(FH); // status
Alert(messages[p].comment);
}
while(!FileIsLineEnding(FH));
p++;
Alert("P = ",p,"; Array length = ", ArraySize(messages));
}
FileClose(FH);
last_read = t;
FileDelete(subfolder+"processedtime.log");
FH = FileOpen(subfolder+"processedtime.log",FILE_BIN);
FileWriteInteger(FH,t,4);
FileClose(FH);
ArrayFree(messages);
}
The code is in tick function in order to test it before taking it out to a function.
The data.csv file is:
Timestamp
Asset
Direction
Price
Stop
Profit
Fraction
Comment
Status
xxx
yyy
SHORT
13240
13240
13220
0.5
yyy SHORT 13240 - taken half at 13220 and stop to breakeven
U
xxx
yyy
SHORT
13240
13262
13040
1.0
55%
DP
The processedtime.log is not being created.
So 2 problems, both of my own making.
Not skipping the header row, simply remedied by inserting
do f = FileReadString(FH);
while(!FileIsLineEnding(FH));
after FileOpen() (easier than altering my source for data.csv), and
forgetting about the asset part of my structure, thus ensuring my structures got out of sync with my lines!! Remedied by adding messages[p].asset = FileReadString(FH); between messages[p].time = t and messages[p].direction = FileReadString(FH);
I am trying to evaluate Saxon-C 1.2.1 HE on CentOS8 and installation seems to have gone ok. Trying out the samples by cd samples/cppTests && build64-linux.sh though leads to a myriad of compilation errors to the tune of the following:
../../Saxon.C.API/SaxonProcessor.h:599:32: error: division ‘sizeof (JNINativeMethod*) / sizeof (JNINativeMethod)’ does not compute the number of array elements [-Werror=sizeof-pointer-div]
gMethods, sizeof(gMethods) / sizeof(gMethods[0]));
Before I summarily and trustfully switched off -Werror=sizeof-pointer-div i checked the source code and what's going on there do seem dubious.
bool registerCPPFunction(char * libName, JNINativeMethod * gMethods=NULL){
if(libName != NULL) {
setConfigurationProperty("extc", libName);
}
if(gMethods == NULL && nativeMethodVect.size()==0) {
return false;
} else {
if(gMethods == NULL) {
//copy vector to gMethods
gMethods = new JNINativeMethod[nativeMethodVect.size()];
}
return registerNativeMethods(sxn_environ->env, "com/saxonica/functions/>
gMethods, sizeof(gMethods) / sizeof(gMethods[0]));
}
return false;
}
more specifically sizeof(gMethods) / sizeof(gMethods[0]) would not seem to calculate anything useful by any margin. The intention was probably rather to output some code that would arrive at the same value as nativeMethodVect.size() but seeing this project's source for the very first time i might be mistaking and the division is in fact intentional ?
I am inclined to guess the intention was in fact closer to b than to a in the following example:
#include <cstdio>
struct test
{
int x, y, z;
};
int main()
{
test *a = new test[32], b[32];
printf("%d %d\n", sizeof(a)/sizeof(a[0]), sizeof(b)/sizeof(b[0]));
return 0;
}
which output 0 32 which is expected as the sizeof(a) gives the size of a pointer not the size of an array's memory region.
That bit of code is to support the feature of user defined extension functions in XSLT stylesheets and XQuery queries. If a user is not using these features then they don't need that bit of code. In fact User defined extension functions is only available in Saxon-PE/C and Saxon-EE/C so it should not be in the Saxon-HE/C code base. I have created the following bug issue to investigate the error above and to https://saxonica.plan.io/issues/4477
I would think the workaround would be to either remove the code in question if the extension function feature is not used or remove the compile flag -Werror=sizeof-pointer-div.
The intent was code is as follows:
jobject JNICALL cppNativeCall(jstring funcName, jobjectArray arguments, jobjectArray argTypes){
//native call code here
}
JNINativeMethod cppMethods[] =
{
{
fname,
funcParameters,
(void *)&cppNativeCall
}
};
bool nativeFound = processor->registerNativeMethods(env, "NativeCall",
cppMethods, sizeof(cppMethods) / sizeof(cppMethods[0]));
I now trying to make Break Even Code trigger more than one time,
example EA entry is 1.28000 and stop loss 1.28500
if current price reach 1.175000(50pips), sl move to break even such as to 1.28000(5pips).
EA will not make more modify order after condition are meet.
so how to trigger break even again if price reach 1.17000(100pips), sl move to (1.175000)(50 pips)
and again price reach 1.165000(150pips),sl move to 1.17000(100pips)
I want to make
BE_B_M(sl move to(example:5))
and
BE_B_T(price reach(example:50))
as variable and every time price reach target variable change to next value
so became
BE_B_M(sl move to(example:50)) and BE_B_T(price reach(example:100))
The entire code is as follows
extern double BE_T_1 = 50;
extern double BE_M_1 = 5;
extern double BE_T_2 = 100;
extern double BE_M_2 = 50;
extern double BE_T_3 = 150;
extern double BE_M_3 = 100;
double BE_S_M;
double BE_S_T;
void MOVE_BE_1()
{
for(int b=OrdersTotal()-1;b>=0;b--)
{
if(OrderSelect(b,SELECT_BY_POS,MODE_TRADES))
if(OrderMagicNumber()!=M_Number)continue;
if(OrderSymbol()==Symbol())
if(OrderType()==OP_BUY)
if(Bid-OrderOpenPrice()>BE_S_T*Pips)
if(OrderOpenPrice()>OrderStopLoss())
if(!OrderModify(OrderTicket(),OrderOpenPrice(),OrderOpenPrice()+(BE_S_M*Pips),OrderTakeProfit(),0,CLR_NONE))
Print("eror");
}
for(int s=OrdersTotal()-1;s>=0;s--)
{
if(OrderSelect(s,SELECT_BY_POS,MODE_TRADES))
if(OrderMagicNumber()!=M_Number)continue;
if(OrderSymbol()==Symbol())
if(OrderType()==OP_SELL)
if(OrderOpenPrice()-Ask>BE_S_T*Pips)
if(OrderOpenPrice()<OrderStopLoss())
if(!OrderModify(OrderTicket(),OrderOpenPrice(),OrderOpenPrice()-(BE_S_M*Pips),OrderTakeProfit(),0,CLR_NONE))
Print("eror");
}
}
i expect sl will move after price reach every 50pips from entry
Here you can put all the 3 break even levels on one function.
Note: you can use 1 for-loop for both OP_BUY and OP_SELL
Here is my OnInit()
// Global variable
double point;
int OnInit()
{
if(Digits == 5 || Digits == 3) point=Point*10;
else point=Point;
return(INIT_SUCCEEDED);
}
Here is the BreakEven() function
//+------------------------------------------------------------------+
//| Break even the trade at 3 levels |
//+------------------------------------------------------------------+
void BreakEven()
{
// get the stop level for that symbol
double stopLevel = SymbolInfoInteger(Symbol(),SYMBOL_TRADE_STOPS_LEVEL)*Point;
for(int i=OrdersTotal()-1;i>=0;i--)
{
if(!OrderSelect(i,SELECT_BY_POS,MODE_TRADES)) continue;
if(OrderMagicNumber()!=M_Number)continue;
if(OrderSymbol()!=Symbol())continue;
if(OrderType()==OP_BUY)
{
double profitPips=Bid-OrderOpenPrice();
double newSL=OrderStopLoss();
if(profitPips>=BE_T_1*point && OrderStopLoss()<OrderOpenPrice()) // Break Even
{
newSL=OrderOpenPrice()+BE_M_1*point;
}
else if(profitPips>=BE_T_3*point) // 150/100
{
newSL=OrderOpenPrice()+BE_M_3*point;
}
else if(profitPips>=BE_T_2*point) // 100/50
{
newSL=OrderOpenPrice()+BE_M_2*point;
}
if(newSL>=OrderStopLoss()+Point && newSL<Bid-stopLevel)
if(!OrderModify(OrderTicket(),OrderOpenPrice(),NormalizeDouble(newSL,Digits),OrderTakeProfit(),0))
Print("Error at BE: ",GetLastError());
}
else if(OrderType()==OP_SELL)
{
double profitPips=OrderOpenPrice()-Ask;
double newSL=OrderStopLoss();
if(profitPips>=BE_T_1*point && (OrderStopLoss()>OrderOpenPrice() || OrderStopLoss()==0)) // Break Even
{
newSL=OrderOpenPrice()-BE_M_1*point;
}
else if(profitPips>=BE_T_3*point) // 150/100
{
newSL=OrderOpenPrice()-BE_M_3*point;
}
else if(profitPips>=BE_T_2*point) // 100/50
{
newSL=OrderOpenPrice()-BE_M_2*point;
}
if(newSL<=OrderStopLoss()-Point && newSL>Ask+stopLevel)
if(!OrderModify(OrderTicket(),OrderOpenPrice(),NormalizeDouble(newSL,Digits),OrderTakeProfit(),0))
Print("Error at BE: ",GetLastError());
}
}
}
I didn't test this myself in a trade, but it should work.