CDL - EVAL - Revision history

HansR: /* Trouble in Paradise */

2026-05-18T12:50:25Z

Trouble in Paradise

← Older revision		Revision as of 12:50, 18 May 2026
Line 76:		Line 76:
	The CUtils compiler then takes the rest and creates the correct javascript function required for Highcharts.		The CUtils compiler then takes the rest and creates the correct javascript function required for Highcharts.

	This took 5 years before the problem was discovered and when it finally showed it took some considerable time before it was understood. See [https://cumulus.hosiene.co.uk/viewtopic.php?t=24257~~&start=15~~ this topic on the forum].		This took 5 years before the problem was discovered and when it finally showed it took some considerable time before it was understood. See [https://cumulus.hosiene.co.uk/viewtopic.php?t=24257 this topic on the forum].

	[[Category:CumulusUtils]]		[[Category:CumulusUtils]]

HansR: /* Trouble in Paradise */

2026-05-18T12:48:29Z

Trouble in Paradise

← Older revision		Revision as of 12:48, 18 May 2026
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	<pre>		<pre>
	Psat1980 EVAL [ 6.112 * EXP(17.67*Temperature/(243.5+Temperature)) ]		Psat1980 EVAL [ 6.112 * EXP(17.67*Temperature/(243.5+Temperature)) ]
	WetBulbTemp Eval [ (0.00066 * Pressure * Temperature + 4098 * Psat1980 / Pow( (Dewpoint + 237.7), 2) * Dewpoint) / ~~(0.00066 * Pressure + 4098 * Psat1980 / Pow((Dewpoint + 237.7),2)) ]~~		WetBulbTemp Eval [ (0.00066 * Pressure * Temperature + 4098 * Psat1980 / Pow( (Dewpoint + 237.7), 2) * Dewpoint) /
		⚫	(0.00066 * Pressure + 4098 * Psat1980 / Pow((Dewpoint + 237.7),2)) ]
	</pre>		</pre>
	''Psat1980'' will be substituted into the ''WetBulbTemp'' equation when needed so it will calculate with Temperature but it required to be the ''Dewpoint'' calculation as you can see from ''CMX svpDP'' function. To account for this issue a Psat1980 equation specifically for the dewPoint needs to be created. So, to calculate the WetBulbTemp correctly, we have to do:		''Psat1980'' will be substituted into the ''WetBulbTemp'' equation when needed so it will calculate with Temperature but it required to be the ''Dewpoint'' calculation as you can see from ''CMX svpDP'' function. To account for this issue a Psat1980 equation specifically for the dewPoint needs to be created. So, to calculate the WetBulbTemp correctly, we have to do:
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	; Specifically for the Wet Bulb Calculation: Psat at Dewpoint		; Specifically for the Wet Bulb Calculation: Psat at Dewpoint
	dewpointPsat1980 EVAL [ 6.112 * EXP(17.67*Dewpoint/(243.5+Dewpoint)) ]		dewpointPsat1980 EVAL [ 6.112 * EXP(17.67*Dewpoint/(243.5+Dewpoint)) ]
			WetBulbTemp Eval [ (0.00066 * Pressure * Temperature + 4098 * dewpointPsat1980 / Pow( (Dewpoint + 237.7), 2) * Dewpoint) /

			(0.00066 * Pressure + 4098 * dewpointPsat1980 / Pow((Dewpoint + 237.7),2)) ]
	; WetbulbTemperature in degr Celsius then becomes
⚫	~~WetBulbTemp~~ ~~Eval~~ [ ~~(0.00066~~ * ~~Pressure~~ * ~~Temperature~~ + ~~4098~~ * ~~dewpointPsat1980~~ / ~~Pow(~~ ~~(Dewpoint~~ + ~~237.7),~~ 2) * ~~Dewpoint)~~ / (0.00066 * Pressure + 4098 * ~~dewpointPsat1980~~ / Pow((Dewpoint + 237.7),2)) ]
	</pre>		</pre>

	The CUtils compiler then takes the rest and creates the correct javascript function required for Highcharts.		The CUtils compiler then takes the rest and creates the correct javascript function required for Highcharts.

	This took 5 years before it was discovered and it finally showed it took some considerable time before it was understood. See [https://cumulus.hosiene.co.uk/viewtopic.php?t=24257&start=15 this topic on the forum].		This took 5 years before the problem was discovered and when it finally showed it took some considerable time before it was understood. See [https://cumulus.hosiene.co.uk/viewtopic.php?t=24257&start=15 this topic on the forum].

	[[Category:CumulusUtils]]		[[Category:CumulusUtils]]

HansR: /* Trouble in Paradise */

2026-05-18T12:45:46Z

Trouble in Paradise

← Older revision		Revision as of 12:45, 18 May 2026
Line 47:		Line 47:

	== Trouble in Paradise ==		== Trouble in Paradise ==
	Equations may seem like functions, and there is a resemblance, but they are not. If you are using an equation in another you must be aware that the plotparameters in the first equation remain the same during substitution. I will explain this through an example of the ''Wet Bulb Temperature calculation'' WBT.		Equations may seem like functions, and there is a resemblance, but they are not. If you are using an equation in another you must be aware that the plotparameters in the first equation remain the same during substitution. I will explain this through an example of the ''Wet Bulb Temperature calculation'' (WBT).

	The WBT is calculated in CMX as:		The WBT is calculated in CMX as:
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	WetBulbTemp Eval [ (0.00066 * Pressure * Temperature + 4098 * Psat1980 / Pow( (Dewpoint + 237.7), 2) * Dewpoint) / (0.00066 * Pressure + 4098 * Psat1980 / Pow((Dewpoint + 237.7),2)) ]		WetBulbTemp Eval [ (0.00066 * Pressure * Temperature + 4098 * Psat1980 / Pow( (Dewpoint + 237.7), 2) * Dewpoint) / (0.00066 * Pressure + 4098 * Psat1980 / Pow((Dewpoint + 237.7),2)) ]
	</pre>		</pre>
	''Psat1980'' will be substituted into the ''WetBulbTemp'' equation when needed but it required to be the ''Dewpoint'' as you can see from ''CMX svpDP'' function. To account for this issue a Psat1980 equation specifically for the dewPoint needs to be created. So, to calculate the WetBulbTemp correctly we have to do:		''Psat1980'' will be substituted into the ''WetBulbTemp'' equation when needed so it will calculate with Temperature but it required to be the ''Dewpoint'' calculation as you can see from ''CMX svpDP'' function. To account for this issue a Psat1980 equation specifically for the dewPoint needs to be created. So, to calculate the WetBulbTemp correctly, we have to do:

	<pre>		<pre>
Line 75:		Line 75:

	The CUtils compiler then takes the rest and creates the correct javascript function required for Highcharts.		The CUtils compiler then takes the rest and creates the correct javascript function required for Highcharts.

			This took 5 years before it was discovered and it finally showed it took some considerable time before it was understood. See [https://cumulus.hosiene.co.uk/viewtopic.php?t=24257&start=15 this topic on the forum].

	[[Category:CumulusUtils]]		[[Category:CumulusUtils]]

HansR at 12:41, 18 May 2026

2026-05-18T12:41:14Z

← Older revision		Revision as of 12:41, 18 May 2026
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	== Introduction ==		== Introduction ==
			{\|align=right
			\|__TOC__
			\|}
	'''The Equations are kind of in continuous BETA, by the nature of all possible combinations and the recursive parsing not all possible equations have been tested (haha)'''		'''The Equations are kind of in continuous BETA, by the nature of all possible combinations and the recursive parsing not all possible equations have been tested (haha)'''

HansR: /* Example & pitfalls */

2026-05-18T12:39:58Z

Example & pitfalls

@@ Line 43: / Line 43: @@
 It is implemented as the JavaScript function ''Math.exp''.
-== Example & pitfalls ==
+== Trouble in Paradise ==
 [[Category:CumulusUtils]]

HansR: /* Functions */

2026-05-18T11:57:58Z

Functions

← Older revision		Revision as of 11:57, 18 May 2026
Line 43:		Line 43:
	It is implemented as the JavaScript function ''Math.exp''.		It is implemented as the JavaScript function ''Math.exp''.

			== Example & pitfalls ==

	[[Category:CumulusUtils]]		[[Category:CumulusUtils]]

HansR: /* EXP */

2025-06-03T03:54:12Z

EXP

← Older revision		Revision as of 03:54, 3 June 2025
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	=== EXP ===		=== EXP ===
	The EXP function provides the power function for the base of the Euler number e.		The EXP function provides the power function for the base of the Euler number e.
	It is implemented as the JavaScript ''Math.exp''.		It is implemented as the JavaScript function ''Math.exp''.

HansR: /* Functions */

2023-02-21T16:33:47Z

Functions

← Older revision		Revision as of 16:33, 21 February 2023
Line 34:		Line 34:
	PLOT ALL AverageTemp EVAL [ SUM(AverageTemp-5) ] colour green Axis DegreeDays		PLOT ALL AverageTemp EVAL [ SUM(AverageTemp-5) ] colour green Axis DegreeDays
	EndChart		EndChart


	=== LN ===		=== LN ===
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	The EXP function provides the power function for the base of the Euler number e.		The EXP function provides the power function for the base of the Euler number e.
	It is implemented as the JavaScript ''Math.exp''.		It is implemented as the JavaScript ''Math.exp''.


	[[Category:CumulusUtils]]		[[Category:CumulusUtils]]

HansR at 16:33, 21 February 2023

2023-02-21T16:33:29Z

← Older revision		Revision as of 16:33, 21 February 2023
Line 35:		Line 35:
	EndChart		EndChart


⚫	[[Category:CumulusUtils]]

	=== LN ===		=== LN ===
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	The EXP function provides the power function for the base of the Euler number e.		The EXP function provides the power function for the base of the Euler number e.
	It is implemented as the JavaScript ''Math.exp''.		It is implemented as the JavaScript ''Math.exp''.

		⚫	[[Category:CumulusUtils]]

HansR: /* Introduction */

2021-12-19T10:11:54Z

Introduction

← Older revision		Revision as of 10:11, 19 December 2021
Line 1:		Line 1:
	== Introduction ==		== Introduction ==
	'''The Equations are in BETA, by the nature of all possible combinations and the recursive parsing not all possible equations have been tested (haha)'''		'''The Equations are kind of in continuous BETA, by the nature of all possible combinations and the recursive parsing not all possible equations have been tested (haha)'''

	The EVAL functions gives the possibility to modify a measurement and plot the result as a separate line. So theoretically one could plot the Dewpoint as a calculated derivative of the Temperature. Also the Growth Degree Days can be simply calculated. The effect of EVAL is that it is not required to transfer data if it can be derived from measurement. Only the measurement needs to be transferred.		The EVAL functions gives the possibility to modify a measurement and plot the result as a separate line. So theoretically one could plot the Dewpoint as a calculated derivative of the Temperature. Also the Growth Degree Days can be simply calculated. The effect of EVAL is that it is not required to transfer data if it can be derived from measurement. Only the measurement needs to be transferred.