Stats_Difference_of

Full Library / Result / Statistics Generator / Stats-Difference_of_Ports
Block Name: Stats-Difference_of_Ports

Code File Location: VisualSim/actor/lib/Stats_Difference

Block Overview

o Compile the statistics for a sequence of the difference of two input scalar values- integer, double or long. For example, the input can be the current throughput. The output at the end of the simulation can show the range of the throughput during the period of the simulation. Similar experiments can be performed on latency, data size, read/write memory etc.

Description

This block updates statistics based on the difference value of two inputs, as opposed to a single input for the Create_Statistics block. The 'stats_data_a' is subtracted from the 'stats_data_b' (a - b), creating the value.

This statistics block can sample every Nth data input. If the user wishes to collect the maximum statistical information, then one would set the 'Sample_Every_Nth_DS' parameter to 1 (default).

The 'Batch_Count_Min_Max' parameter is normally set to 1 0.0 100.0, where the first number indicates the number of batches (1), the second number indicates the start time (0.0), the last number indicates the stop time (100.0). The stop time can also be set to 'tstop', which will be interpreted by the block to insert the end of the simulation time.

The "Statistics_Name" field is printed in the BLOCK field of the output data structure.

When the stats_trigger port is triggered, current values of the statistics are reported on the stats_out output port. When the stats_reset input port is triggered, all statistics in the block is reset. Both these ports can be fired at any time during the simulation. The Histo port will output the histogram of the sequence values- X-axis will be the value and Y-axis will be the number of occurances of each column.

Refer Profile_Statistics Demo Model.

Data Structure of the Statistics output:

BLOCK Stats_Basic             DS_NAME   Basic_Stats
DELTA 0.0                     TIME      5.625067999999972E-7
INDEX 0                       ID        69

Statistic_Name                String    Queue_Length
Number_Values                 int       2513
Min_Value                     double    0.0
Mean_Value                    double    1.112216474333466
StDev_Value                   double    0.8256330697465197
Max_Value                     double    4.0
Mean_95_Confidence            double    0.0322803536050639
Data_95_StDev_196s            double    1.618208684980151

Statistic Name	Explanation	Mathematical Equation	Sample Values	Type
Statistic_Name	Unique name to identify the output. Added to the field called Statistics_Name in the output data structure.	-	Queue_Length	String
Number_Values	Number of entries to this block and used to calculate the statistics.	-	2513	int
Min_Value	Minimum queue size during the simulation. (Value opposed to time delay or occupancy).	// Obtain Min for X, where X0 = Double.MAX_VALUE if (Xn < Xn – 1) Xmin = Xn	0.0	double
Mean_Value	Mean/Average queue size during the simulation (Value opposed to time delay or occupancy).	// Obtain Mean for X Xµ = (1 / n) * (X1 + X2 + … + Xn)	1.112216474333466	double
StDev_Value	Standard Deviation from the Mean queue size during the simulation.(Value opposed to time delay or occupancy).	// Obtain Standard Deviation for X Xσ = Math.sqrt ((1 / n) * ((X1 - Xµ)2 + (X2 - Xµ)2 + … + (Xn - Xµ)2)) STDEV_90_PCT = 1.6448530004790 STDEV_95_PCT = 1.9599610823207 STDEV_99_PCT = 2.5758345145732	0.8256330697465197	double
Max_Value	Maximum queue size consumed during the simulation. (Value opposed to time delay or occupancy).	// Obtain Max for X, where X0 = Double.MIN_VALUE if (Xn > Xn – 1) Xmax = Xn	4.0	double
Mean_95_Confidence	The 95% confidence intervals is used to indicate the reliability of an estimate. How likely the interval is to contain the parameter is determined by the confidence level or confidence coefficient. The confidence level is 95%.	// Obtain 95% Confidence Interval for Mean. Xµ95 = STDEV_95_PCT * (Xσ / Math.sqrt(n)))	0.0322803536050639	double
Data_95_StDev_196s	This is the standard deviation of the confidence interval.	// Obtain 95% Confidence Interval for Mean. Xµ95 = STDEV_95_PCT * (Xσ / Math.sqrt(n)))	1.618208684980151	double

Where n is the number of samples and X is occupancy or delay.

Field Detail

Statistic_Name

public Parameter Statistic_Name

Parameter, Name of Statistic Variable.

Sample_Every_Nth_DS

public Parameter Sample_Every_Nth_DS

Parameter, Sample every Nth data structure.

Batch_Count_Min_Max

public Parameter Batch_Count_Min_Max

Parameter, Collect N batches (int), starting at Min time (double), end at Max time (double). The values can be a string or a parameter. The number of batches can be 1.

Statistic_Type

public StringAttribute Statistic_Type

Attribute, Statistic Type.

stats_data_a

public TypedIOPort stats_data_a

Input port, data sample a, larger value.

stats_data_b

public TypedIOPort stats_data_b

Input port, data sample b, subtracted from larger value (a).

stats_trigger

public TypedIOPort stats_trigger

Input port, triggers accumulated atatistics.

stats_reset

public TypedIOPort stats_reset

Input port, reset all internal statistics.

histo_output

public VisualSim.actor.TypedIOPort histo_output

Output port, passes incoming integer or double value as a double value. The values can be plotted on a histogram.

output

public TypedIOPort output

Output port, Statistics Summaries, based on 'Statistic_Type'.

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Stats_Difference_of_Ports