/DEQATN
Optimization Keyword Specifies one or more equations for use in optimization.
Format
(1)  (2)  (3)  (4)  (5)  (6)  (7)  (8)  (9)  (10) 

/DEQATN/eqn_ID  
title  
EQN(1); EQN(2); ...  
...  
EQN(n1); EQN(n) 
Definitions
Field  Contents  SI Unit Example 

eqn_ID  Design equation
identifier. (Integer > 0) 

title  Title. (Character, maximum 100 characters) 

EQN(i)  ith
equation. (Character string) 
Example
#12345678910
/DRESP1/1
u_in
### RTYPE=5: Displacement
### PTYPE=1: Node
### ATTA=1 : Translational displacement in Xdirection
### ATTI=103 : 103 is node group identifier is due to PTYPE = 1
#12345678910
# RTYPE PTYPE REGION ATTA ATTB ATTI
5 1 1 103
#12345678910
/DRESP1/2
u_out
### RTYPE=5: Displacement
### PTYPE=1: Node
### ATTA=1 : Translational displacement in Xdirection
### ATTI=104 : 104 is node group identifier is due to PTYPE = 1
#12345678910
# RTYPE PTYPE REGION ATTA ATTB ATTI
5 1 1 104
#12345678910
/DRESP2/4
dresp2
### EQID=1: /DEQATN identifier is 1
### VARTYPE1=3: Indicates the type of variables is 3 (DRESP1)
### ID1=1: first Variable(x) is ID1=1 in DRESP1 (dx in node group 103)
### ID2=2: second Variable(y) is ID2=2 in DRESP1 (dx in node group 104)
# FUNC EQID REGION
1
# VARTYPE1 ID1 ID2 ID1 ID2 ID1 ID2 ID1 ID2 ID1
3 1 2
#12345678910
/DEQATN/1
deqatn
# EQUATIONS
dm(x,y)=(x+y)/2.
#12345678910
Comments
 Blank characters in the equation have no effect, even within a constant, variable or function name. Lower and upper case letters are equivalent.
 There must be only one variable at
the lefthand side of each equation in any equation card. The variable of the first
equation must be followed by an argument listed in the following
format:
v1(x1,x2,…,xn) = expression(x1,x2,…,xn); v2 = expression(x1,x2,…,xn,v1); … vi = expression(x1,x2,…,xn,v1,v2,…,vi1); … vn = expression(x1,x2,…,xn,v1,v2,…,vn1);
Where,
vi
is the variable of equation i. (x1
,x2
, ...,xn
) is the argument list for variablev1
. (v1
,v2
,...,vi1
) is the variable list which corresponds to the result of equation 1 through equation I1.  Constants can
be specified in a format of either integer or floating point. A floating point
number can be in a format of either normal decimalpoint format (3.90) or scientific
notation (2.0E3), which means 2x10^{3}.The list of supported mathematical functions is:
 Oneargument Functions
 abs(x)
 Absolute value
 acos(x)
 Arccosine
 acosh(x)
 Hyperbolic arccosine
 asin(x)
 Arcsine
 asinh(x)
 Hyperbolic arcsine
 atan(x)
 Arctangent
 atanh(x)
 Hyperbolic arctangent
 cos(x)
 Cosine
 cosh(x)
 Hyperbolic cosine
 exp(x)
 Exponential
 log(x)
 Natural logarithm
 log10(x)
 Common logarithm
 pi(x)
 Multiples of π
 sin(x)
 Sine
 sinh(x)
 Hyperbolic sine
 int (x)
 Real to integer conversion
 sqrt(x)
 Square root
Twoargument functions:Multiargument functions:  The
supported operators are:
Symbol Meaning Example + binary + x + y  binary  x  y * multiplication x * y / division x / y ** power x ** y + unary + +1.0  unary  1.0  The precedence of
mathematical calculations follows the rules of Fortran
language. Parenthesis has a higher priority in the order of precedence than the
operators listed above. Two consecutive operators are acceptable only if the second
one is unary, plus or minus.Examples of operator precedence:
 Expression
 Result
 2**3
 0.128
 1 / 2 + 3
 3.5
 2*34
 2.0
 2**3**2
 512.0
 2 + 5
 3.0
 2 * 5
 10.0
 2  5
 7.0
 2/3/4
 0.16666666....
 2/(3/4)
 2.6666666...
 Functions can be defined in a layered format, for example, min(sin(x1), x2), with no limit on the number of layers.
 The /DEQATN entry is referenced by /DRESP2 entry.