IPMS Calculation Manual (PDF 108 KB)

Formulae available in the IPMS Client Equation Editor 1. OBJECTIVE To provide details of the format and expressions that can be used within the Meniscus IPMS Client Calculation Editor. 2. CALCULATION FORMAT The format for any calculation will contain one or more of the following: Expression: This is the command that extracts either a single reading or a range of readings from the database. Calculation: This is the command that undertakes a specific scientific function on the readings returned from the database. Meterid: This is the meterid of the parameter to be used in the calculation. StartDate: The first date that should be used in the calculation. EndDate: The last date that should be used in the calculation. Variable: This is a variable (normally numeric) use in a Calculation Important: A calculation using today’s value of the reading for a parameter will use the expression ‘today’ for either the StartDate or the EndDate. To use the previous days reading will use the expression ‘today-1’ etc. 3. CALCULATIONS WORKING ON A SINGLE READING 3.1. Expressions returning a single reading Format: Expression(Meterid,StartDate) The following Expressions return a single reading. If required a number of calculations can then be applied to this reading to calculate a number of statistical and mathematical values. Available Expressions Expression Description data Returns calculated data rawdata Returns raw data target Returns target data cost Returns the cost targetcost Returns the target Cost 3.1.1. Example Data(1748,today) this returns today’s value for meter 1748 Important. In the normal course of using IPMS is unlikely that you will use any expression other than Data 3.2. Calculations requiring 1 parameter Format: Calculation(Expression(Meterid,StartDate)) Available Calculation Calculations Description log Natural logarithm log10 Base 10 logarithm exp Exponential ceil Round number up to the highest integer floor Round number down to the lowest integer Date: 20th November 2003 Meniscus Systems Ltd Page 1 of 2 Formulae available in the IPMS Client Equation Editor v1.1.doc Formulae available in the IPMS Client Equation Editor Date: 20th November 2003 Meniscus Systems Ltd Page 2 of 2 Formulae available in the IPMS Client Equation Editor v1.1.doc sqrt Square root 3.2.1. Example Log(data(1247,today-1)) – Generates yesterday’s value of the natural log for meter 1247. 3.3. Calculations requiring 2 parameters Format: Calculation(Expression(Meterid,StartDate),Variable) Available Calculation Calculations Description Pow Calculates the power of the parameter 3.3.1. Example Pow(data(1524,today)3) – Raises the today’s value of meter 1524 to the power of 3 4. CALCULATIONS WORKING ON A SET OF READINGS Format: Calculation(Expression(Meterid,StartDate,EndDate)) 4.1. Expressions returning a set of readings The following Expressions return a set of readings. If required a number of Calculations can then be applied to these readings to calculate a number of statistical and mathematical values for the whole set. Available Expressions Expression Description dataset Returns a set of calculated readings rawdataset Returns a set of raw readings targetset Returns a set of target readings costset Returns a set of cost readings targetcostset Returns a set of target cost readings 4.2. Calculations requiring 1 parameter Available Calculations Calculations Description stddev Calculates the standard deviation mean Calculates the mean min Calculates the minimum value max Calculates the maximum value sum Calculates the sum of the values 4.2.1. Examples Mean(dataset(1654,today,today-7)) – Calculates the mean value for meter 1654 for the last 7 days Sum(costset(1624,today,today-30)) – Calculates the sum of the cost for meter 1624 over the last 30 days OBJECTIVE CALCULATION FORMAT CALCULATIONS WORKING ON A SINGLE READING Expressions returning a single reading Example Calculations requiring 1 parameter Example Calculations requiring 2 parameters Example CALCULATIONS WORKING ON A SET OF READINGS Expressions returning a set of readings Calculations requiring 1 parameter Examples