GIAC commands

Dynamic Command Invocation

Call any of GIAC's 2200+ commands dynamically:

using Giac

@giac_var x
expr = x^2 - 1

# Function syntax with invoke_cmd (works for ALL commands)
result = invoke_cmd(:factor, expr)           # (x-1)*(x+1)
deriv = invoke_cmd(:diff, expr, x)           # 2*x
integral = invoke_cmd(:integrate, expr, x)   # x^3/3-x

# Method syntax on GiacExpr (equivalent to invoke_cmd)
result = expr.factor()                     # (x-1)*(x+1)
deriv = expr.diff(x)                       # 2*x

# Chaining methods
@giac_var a b
result = ((a+b)^2).expand()
result = ((a+b)^2).expand().factor()
# or using |> operator
(a+b)^2 |> expand
(a+b)^2 |> expand |> factor

# Natural Julia syntax with Base extensions
@giac_var y
sin(y)         # sin(y)
cos(y)         # cos(y)
exp(y)         # exp(y)
log(y)         # ln(y)
sqrt(y)        # sqrt(y)
sin(y) + cos(y)  # sin(y)+cos(y)

Commands Submodule

Giac.jl provides three ways to access GIAC's 2200+ commands via the Giac.Commands submodule:

1. Qualified Access

Access commands via Giac.Commands.commandname:

using Giac

@giac_var x
expr = x^2 - 1

# Access commands via Giac.Commands
Giac.Commands.factor(expr)          # (x-1)*(x+1)
Giac.Commands.expand((x+1)^2)  # x^2+2*x+1
Giac.Commands.diff(expr, x)         # 2*x
Giac.Commands.integrate(expr, x)    # x^3/3-x
Giac.Commands.ifactor(120)  # 2^3*3*5

2. Selective Import

Import specific commands you need:

using Giac
using Giac.Commands: factor, expand, diff, integrate

@giac_var x
expr = x^2 - 1

# Direct function syntax (no prefix needed)
factor(expr)              # (x-1)*(x+1)
expand((x+1)^2)  # x^2+2*x+1
diff(expr, x)             # 2*x
integrate(expr, x)        # x^3/3-x

3. Full Import (Interactive Use)

Import all ~2000+ commands for interactive exploration:

using Giac
using Giac.Commands  # Imports ALL exportable commands

@giac_var x
factor(x^2 - 1)    # (x-1)*(x+1)
ifactor(120)       # 2^3*3*5
nextprime(100)     # 101
airy_ai(0)         # Airy function

# Discover available commands
exportable_commands()            # ~2000+ command names

invoke_cmd for ALL Commands

For commands that conflict with Julia (like sin, cos, eval, det), use invoke_cmd:

using Giac

@giac_var k n

# Conflicting commands must use invoke_cmd
invoke_cmd(:eval, giac_eval("2+3"))      # 5
invoke_cmd(:sin, giac_eval("pi/6"))      # 1/2
invoke_cmd(:det, giac_eval("[[1,2],[3,4]]"))  # -2
invoke_cmd(:det, giac_eval("[[a,b],[c,d]]"))  # a*d-b*c
invoke_cmd(:sum, k, k, giac_eval("1"), n)  # 1/2*n^2+1/2*n
invoke_cmd(:product, k, k, giac_eval("1"), n)  # n!

# invoke_cmd works for ANY command
invoke_cmd(:factor, giac_eval("x^2-1"))  # (x-1)*(x+1)

Commands That Conflict with Julia

Some GIAC commands have the same name as Julia built-ins. These are not exported from Giac.Commands to avoid shadowing Julia's functions:

Use invoke_cmd(:name, args...) for these commands. A warning is shown on first use to remind you:

invoke_cmd(:eval, giac_eval("2+3"))
# ┌ Warning: GIAC command 'eval' conflicts with Julia (builtin).
# │ Use invoke_cmd(:eval, args...) to call it.