Duyuru:
15 Nisan 2025'ten önce Earth Engine'i kullanmak için kaydedilen tüm ticari olmayan projelerin Earth Engine erişimini sürdürmek için
ticari olmayan uygunluğu doğrulaması gerekir.
ee.Number.expression
Koleksiyonlar ile düzeninizi koruyun
İçeriği tercihlerinize göre kaydedin ve kategorilere ayırın.
Sayısal bir ifadeyi hesaplar.
Kullanım | İadeler |
---|
ee.Number.expression(expression, vars) | Sayı |
Bağımsız Değişken | Tür | Ayrıntılar |
---|
expression | Dize | Değerlendirilecek matematiksel ifade dizesi. İfadeler, standart aritmetik, Boole ve ilişkisel operatörlerin yanı sıra Number'daki tüm işlevleri, "vars" sözlüğünden alt öğeleri çıkarmak için kullanılan "." operatörünü ve matematiksel sabitler Math.PI ve Math.E'yi de destekler. |
vars | Sözlük, varsayılan: null | İfadede kullanılabilecek adlandırılmış değerlerin sözlüğü. |
Örnekler
Kod Düzenleyici (JavaScript)
// A dictionary of variables to use in expression.
var variables = {x: 5, y: 10};
// Arithmetic operators.
print('x + y',
ee.Number.expression('x + y', variables));
print('x - y',
ee.Number.expression('x - y', variables));
print('x * y',
ee.Number.expression('x * y', variables));
print('x / y',
ee.Number.expression('x / y', variables));
print('x ** y',
ee.Number.expression('x ** y', variables));
print('x % y',
ee.Number.expression('x % y', variables));
// Logical operators.
print('x || y',
ee.Number.expression('x || y', variables));
print('x && y',
ee.Number.expression('x && y', variables));
print('!(x)',
ee.Number.expression('!(x)', variables));
// Relational operators.
print('x > y',
ee.Number.expression('x > y', variables));
print('x >= y',
ee.Number.expression('x >= y', variables));
print('x < y',
ee.Number.expression('x < y', variables));
print('x <= y',
ee.Number.expression('x <= y', variables));
print('x == y',
ee.Number.expression('x == y', variables));
print('x != y',
ee.Number.expression('x != y', variables));
// Conditional (ternary) operator.
print('(x < y) ? 100 : 1000)',
ee.Number.expression('(x < y) ? 100 : 1000', variables));
// Constants in the expression.
print('100 * (x + y)',
ee.Number.expression('100 * (x + y)', variables));
// JavaScript Math constants.
print('Math.PI',
ee.Number.expression('Math.PI', null));
print('Math.E',
ee.Number.expression('Math.E', null));
// Dot notation to call on child elements.
print('Use dot notation to call on child elements',
ee.Number.expression('vals.x * vals.y', {vals: variables}));
// ee.Number functions.
print('Use ee.Number add: add(x, y)',
ee.Number.expression('add(x, y)', variables));
print('Use ee.Number add and subtract: subtract(add(x, y), 5)',
ee.Number.expression('subtract(add(x, y), 5)', variables));
Python kurulumu
Python API'si ve etkileşimli geliştirme için geemap
kullanımı hakkında bilgi edinmek üzere
Python Ortamı sayfasına bakın.
import ee
import geemap.core as geemap
Colab (Python)
# A dictionary of variables to use in expression.
variables = {'x': 5, 'y': 10}
# Arithmetic operators.
print('x + y:',
ee.Number.expression('x + y', variables).getInfo())
print('x - y:',
ee.Number.expression('x - y', variables).getInfo())
print('x * y:',
ee.Number.expression('x * y', variables).getInfo())
print('x / y:',
ee.Number.expression('x / y', variables).getInfo())
print('x ** y:',
ee.Number.expression('x ** y', variables).getInfo())
print('x % y:',
ee.Number.expression('x % y', variables).getInfo())
# Logical operators.
print('x || y:',
ee.Number.expression('x || y', variables).getInfo())
print('x && y:',
ee.Number.expression('x && y', variables).getInfo())
print('!(x):',
ee.Number.expression('!(x)', variables).getInfo())
# Relational operators.
print('x > y:',
ee.Number.expression('x > y', variables).getInfo())
print('x >= y:',
ee.Number.expression('x >= y', variables).getInfo())
print('x < y:',
ee.Number.expression('x < y', variables).getInfo())
print('x <= y:',
ee.Number.expression('x <= y', variables).getInfo())
print('x == y:',
ee.Number.expression('x == y', variables).getInfo())
print('x != y:',
ee.Number.expression('x != y', variables).getInfo())
# Conditional JavaScript (ternary) operator.
print('(x < y) ? 100 : 1000):',
ee.Number.expression('(x < y) ? 100 : 1000', variables).getInfo())
# Constants in the expression.
print('100 * (x + y):',
ee.Number.expression('100 * (x + y)', variables).getInfo())
# JavaScript Math constants.
print('Math.PI:',
ee.Number.expression('Math.PI', None).getInfo())
print('Math.E:',
ee.Number.expression('Math.E', None).getInfo())
# Dot notation to call on child elements.
print('Use dot notation to call on child elements:',
ee.Number.expression('vals.x * vals.y', {'vals': variables}).getInfo())
# ee.Number functions.
print('Use ee.Number add. add(x, y):',
ee.Number.expression('add(x, y)', variables).getInfo())
print('Use ee.Number add and subtract. subtract(add(x, y), 5):',
ee.Number.expression('subtract(add(x, y), 5)', variables).getInfo())
Aksi belirtilmediği sürece bu sayfanın içeriği Creative Commons Atıf 4.0 Lisansı altında ve kod örnekleri Apache 2.0 Lisansı altında lisanslanmıştır. Ayrıntılı bilgi için Google Developers Site Politikaları'na göz atın. Java, Oracle ve/veya satış ortaklarının tescilli ticari markasıdır.
Son güncelleme tarihi: 2025-07-29 UTC.
[null,null,["Son güncelleme tarihi: 2025-07-29 UTC."],[[["\u003cp\u003e\u003ccode\u003eee.Number.expression\u003c/code\u003e computes a numeric expression provided as a string.\u003c/p\u003e\n"],["\u003cp\u003eIt supports standard arithmetic, boolean, relational operators, as well as \u003ccode\u003eee.Number\u003c/code\u003e functions, and mathematical constants.\u003c/p\u003e\n"],["\u003cp\u003eA dictionary of variables can be passed to the function to be used within the expression.\u003c/p\u003e\n"],["\u003cp\u003eDot notation can be utilized within the expression to access child elements of variables provided in the dictionary.\u003c/p\u003e\n"]]],["`ee.Number.expression` evaluates a mathematical expression string. It accepts an `expression` string and an optional `vars` dictionary containing named values. The expression supports arithmetic, boolean, and relational operators, as well as functions found in `ee.Number` and constants like `Math.PI` and `Math.E`. Dot notation accesses nested dictionary elements. The function returns a numerical result, allowing complex computations. Examples include adding, subtracting, multiplying, applying logical operations, and conditional logic.\n"],null,["# ee.Number.expression\n\nComputes a numeric expression.\n\n\u003cbr /\u003e\n\n| Usage | Returns |\n|----------------------------------------------|---------|\n| `ee.Number.expression(expression, `*vars*`)` | Number |\n\n| Argument | Type | Details |\n|--------------|---------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|\n| `expression` | String | A mathematical expression string to be evaluated. In addition to the standard arithmetic, boolean and relational operators, expressions also support any function in Number, the '.' operator to extract child elements from the 'vars' dictionary, and mathematical constants Math.PI and Math.E. |\n| `vars` | Dictionary, default: null | A dictionary of named values that can be used in the expression. |\n\nExamples\n--------\n\n### Code Editor (JavaScript)\n\n```javascript\n// A dictionary of variables to use in expression.\nvar variables = {x: 5, y: 10};\n\n// Arithmetic operators.\nprint('x + y',\n ee.Number.expression('x + y', variables));\nprint('x - y',\n ee.Number.expression('x - y', variables));\nprint('x * y',\n ee.Number.expression('x * y', variables));\nprint('x / y',\n ee.Number.expression('x / y', variables));\nprint('x ** y',\n ee.Number.expression('x ** y', variables));\nprint('x % y',\n ee.Number.expression('x % y', variables));\n\n// Logical operators.\nprint('x || y',\n ee.Number.expression('x || y', variables));\nprint('x && y',\n ee.Number.expression('x && y', variables));\nprint('!(x)',\n ee.Number.expression('!(x)', variables));\n\n// Relational operators.\nprint('x \u003e y',\n ee.Number.expression('x \u003e y', variables));\nprint('x \u003e= y',\n ee.Number.expression('x \u003e= y', variables));\nprint('x \u003c y',\n ee.Number.expression('x \u003c y', variables));\nprint('x \u003c= y',\n ee.Number.expression('x \u003c= y', variables));\nprint('x == y',\n ee.Number.expression('x == y', variables));\nprint('x != y',\n ee.Number.expression('x != y', variables));\n\n// Conditional (ternary) operator.\nprint('(x \u003c y) ? 100 : 1000)',\n ee.Number.expression('(x \u003c y) ? 100 : 1000', variables));\n\n// Constants in the expression.\nprint('100 * (x + y)',\n ee.Number.expression('100 * (x + y)', variables));\n\n// JavaScript Math constants.\nprint('Math.PI',\n ee.Number.expression('Math.PI', null));\nprint('Math.E',\n ee.Number.expression('Math.E', null));\n\n// Dot notation to call on child elements.\nprint('Use dot notation to call on child elements',\n ee.Number.expression('vals.x * vals.y', {vals: variables}));\n\n// ee.Number functions.\nprint('Use ee.Number add: add(x, y)',\n ee.Number.expression('add(x, y)', variables));\nprint('Use ee.Number add and subtract: subtract(add(x, y), 5)',\n ee.Number.expression('subtract(add(x, y), 5)', variables));\n```\nPython setup\n\nSee the [Python Environment](/earth-engine/guides/python_install) page for information on the Python API and using\n`geemap` for interactive development. \n\n```python\nimport ee\nimport geemap.core as geemap\n```\n\n### Colab (Python)\n\n```python\n# A dictionary of variables to use in expression.\nvariables = {'x': 5, 'y': 10}\n\n# Arithmetic operators.\nprint('x + y:',\n ee.Number.expression('x + y', variables).getInfo())\nprint('x - y:',\n ee.Number.expression('x - y', variables).getInfo())\nprint('x * y:',\n ee.Number.expression('x * y', variables).getInfo())\nprint('x / y:',\n ee.Number.expression('x / y', variables).getInfo())\nprint('x ** y:',\n ee.Number.expression('x ** y', variables).getInfo())\nprint('x % y:',\n ee.Number.expression('x % y', variables).getInfo())\n\n# Logical operators.\nprint('x || y:',\n ee.Number.expression('x || y', variables).getInfo())\nprint('x && y:',\n ee.Number.expression('x && y', variables).getInfo())\nprint('!(x):',\n ee.Number.expression('!(x)', variables).getInfo())\n\n# Relational operators.\nprint('x \u003e y:',\n ee.Number.expression('x \u003e y', variables).getInfo())\nprint('x \u003e= y:',\n ee.Number.expression('x \u003e= y', variables).getInfo())\nprint('x \u003c y:',\n ee.Number.expression('x \u003c y', variables).getInfo())\nprint('x \u003c= y:',\n ee.Number.expression('x \u003c= y', variables).getInfo())\nprint('x == y:',\n ee.Number.expression('x == y', variables).getInfo())\nprint('x != y:',\n ee.Number.expression('x != y', variables).getInfo())\n\n# Conditional JavaScript (ternary) operator.\nprint('(x \u003c y) ? 100 : 1000):',\n ee.Number.expression('(x \u003c y) ? 100 : 1000', variables).getInfo())\n\n# Constants in the expression.\nprint('100 * (x + y):',\n ee.Number.expression('100 * (x + y)', variables).getInfo())\n\n# JavaScript Math constants.\nprint('Math.PI:',\n ee.Number.expression('Math.PI', None).getInfo())\nprint('Math.E:',\n ee.Number.expression('Math.E', None).getInfo())\n\n# Dot notation to call on child elements.\nprint('Use dot notation to call on child elements:',\n ee.Number.expression('vals.x * vals.y', {'vals': variables}).getInfo())\n\n# ee.Number functions.\nprint('Use ee.Number add. add(x, y):',\n ee.Number.expression('add(x, y)', variables).getInfo())\nprint('Use ee.Number add and subtract. subtract(add(x, y), 5):',\n ee.Number.expression('subtract(add(x, y), 5)', variables).getInfo())\n```"]]